gacha-event-tracker/AGENTS.md

# AGENTS.md

This file provides guidance to coding agents working in this repository. It is the working
agreement: what this project is, the constraints it holds to, and the rules that are not visible
from the code alone. Read it before changing anything.

`CLAUDE.md` points here, so Claude Code picks it up too — keep the guidance in this file and leave
that one a pointer.

## Read the docs before changing the thing they describe

This file is the working agreement, not the specification. `docs/` holds the reasoning, and it is
written for whoever touches that area next — reading the relevant one first is the difference
between repairing a rule and rediscovering it the expensive way.

| Doc | What it settles | Read it before |
|---|---|---|
| `docs/PRD.md` | What the product is for, feature by feature (F1–F14), and the quality bar for dates | Changing behaviour a reader can see, or arguing something is out of scope |
| `docs/DATA-MODEL.md` | `GachaEvent`, the SQLite tables, every `localStorage` key space, the export format | Touching `src/shared/schema.ts`, an ID scheme, a stored key, or the game/reset table |
| `docs/INGESTION.md` | The six pipeline stages, the parser/adapter/merge layering, date formats, the review gate | Adding a source, writing or repairing a parser, or changing the fetch runner |
| `docs/ARCHITECTURE.md` | Process shape, file layout, request paths, offline and update mechanics | Moving files, adding a route, or changing the service worker |
| `docs/FEEDBACK.md` | What readers actually said about the first release, and the work it argues for | Deciding what to build next |

Two rules that follow from that:

- **The docs are part of the change.** A change that makes a sentence in `docs/` false is not
  finished until that sentence is fixed. They are the only record of *why*, so drift costs the next
  agent the whole reasoning, not just a detail.
- **When this file and a doc disagree, that is a bug — say so.** Neither one silently wins. This
  file summarises; the doc holds the argument, so fix whichever is actually wrong rather than
  reconciling them in your head and moving on.

## What this is

A web app that aggregates live and upcoming events across popular gacha games, plots them on a
calendar, sorts them by end date or by what the reader is partway through, tracks day-by-day
progress on events that repeat daily, and lets a user mark events completed.

**Status: working app, refreshing itself on a schedule.** Schema, six parsers, fourteen sources across
thirteen games, the full interface, offline support, a static server, a Docker image and CI all exist and
are tested. The refresh runner (`bun run refresh`) fetches, caches raw snapshots and rebuilds the
feed; `.github/workflows/refresh.yml` runs it twice a day and commits only when a page actually
changed. The SQLite layer and the review queue are still specified in `docs/` but not built, so the
feed is a static JSON file built from snapshots, falling back to checked-in fixtures.

## Three constraints that shape everything

1. **No accounts, no logins, no user records.** Completion state lives in the browser's
   `localStorage`, keyed by event ID. There is no user table and no session. Any request implying
   "sync across devices" is solved with export/import JSON, not a server-side user.
2. **No LLM in the pipeline.** Event data is extracted by deterministic code-based parsers only.
   There is no Anthropic dependency, no API key, and no per-run inference cost. A source that
   cannot be parsed deterministically does not get an adapter — see `docs/INGESTION.md` § No LLM.
3. **A server is allowed** (Bun) and owns fetching, parsing, and SQLite. The client only ever calls
   this app's own `/api/*`.

## Stack

| Layer | Choice |
|---|---|
| Runtime / server / bundler / test runner | Bun 1.3 (`Bun.serve`, `bun:sqlite`, `bun test`, `bun build`) |
| UI | React 19 + TypeScript (strict) + Tailwind |
| Storage | SQLite via `bun:sqlite` (gitignored — `*.sqlite`) |
| Validation | Zod — one schema module shared by server and client |

The only runtime dependency is `zod`. Do not add a bundler, test runner, HTTP client, or HTML
parsing library — Bun covers all four. `tsconfig.json` runs `strict` plus
`noUncheckedIndexedAccess` and `exactOptionalPropertyTypes`.

## Commands

```bash
bun install
bun test                      # full suite, offline, no network, no build needed
bun run typecheck             # tsc --noEmit
bun run dev                   # build then serve on :3000
bun run build                 # feed + css + js + static into public/

# Fetch sources and refresh the snapshots. Makes real requests — see § Scraping
# conduct before running it, and prefer --dry-run.
bun run refresh --dry-run
bun run refresh --only genshin-game8-events

# Run one source against its fixture (offline, free)
bun run parse genshin-game8-events fixtures/genshin/game8-events-2026-08-14.html
bun run parse endfield-wikigg-events fixtures/endfield/wikigg-events-2026-08-15.html --json

# Single test file / single test
bun test test/dates.test.ts
bun test --test-name-pattern "year-less"

# Hosting under a subpath (GitHub Pages)
BASE_PATH=/gacha-event-tracker/ bun run build
```

**Tests must never need build output.** They run before `bun run build` in CI; anything reading
`public/` must create its own fixture tree instead.

`bun run parse ... --json` is also how `.expected.json` fixtures are regenerated after an
intentional parser change. Regenerating them makes the test self-consistent, not correct — always
re-verify a sample against the live page afterward.

## Current state of the code

```
src/shared/       schema.ts (the contract), time.ts, daily.ts, effort.ts, games.ts, feed.ts
                  custom.ts — reader-authored games and events, and their key spaces
src/ingest/       html.ts, dates.ts (twelve formats), merge.ts, sanitize.ts, robots.ts, snapshots.ts
  parsers/        game8.ts, wikigg.ts, akwiki.ts, fandom.ts, bawiki.ts, holodori.ts — keyed by SITE, not game
  adapters/       index.ts — SOURCES registry binding url+game+parser, and the sanitize seam
src/client/       React app, service worker, manifest
  state/          progress, daily log, ignores, prefs, sort — all localStorage
                  useCustom.ts — the reader's own games and events (PRD F13)
                  lens.ts — who sees which rows (focus, outstanding, next-to-expire); pure
scripts/          build-feed.ts, build-static.ts, parse-fixture.ts (offline), refresh-sources.ts (fetches)
serve.ts          static server + /api/health
test/             560 tests
fixtures/<game>/  raw HTML + .expected.json per source — pinned, kept forever
snapshots/        current page per source, rewritten by refresh — see its README
```

Not yet built: the SQLite layer and the review UI. Everything upstream of them runs as files on
disk.

## Domain rules that are not obvious from the code

These come from how gacha games actually schedule things, and they cause most bugs here:

- **Store every timestamp as UTC ISO 8601.** Sources publish in a mix of UTC+8, server-local, and
  "after maintenance".
- **Banner ends are usually global and simultaneous; event ends are usually per-region.** Character
  banners end at one instant worldwide; story/login events end at each region's daily reset (Asia /
  America / Europe differ by hours). `regionScoped` and `regionEnds` exist for this — do not
  collapse them into one timestamp.
- **`endsAt: null` is a correct, expected value.** An event whose end is genuinely unannounced gets
  `endsAt: null` and `endPrecision: "unknown"`. **Never invent a plausible date to satisfy a
  non-null type.** This is the worst failure mode this codebase has, because the user's entire
  reason for visiting is trusting the end date.
- **Patch cycles are ~6 weeks.** Any event over 180 days is a parse error, not a long event. The
  validator and the tests both reject it.

## Working on parsers

- **Parsers are pure.** No network, no `Date.now()`, no randomness — time arrives as `ctx.now`.
  This is what makes fixture tests meaningful; a parser that reads the clock cannot be tested.
- **Skip, never guess.** Every function in `dates.ts` returns `null` rather than inferring a missing
  year, month, or end. `readColumnTable` drops a row it cannot date. An omitted event is a
  recoverable disappointment; a confidently wrong date is the failure this product exists to prevent.
- **Parsers are keyed by site, not game.** One `game8` parser serves eight sources and `fandom` two;
  `wikigg`, `akwiki`, `bawiki` and `holodoriwiki` serve one each — the first two share a host family
  and have entirely different templates, and the last two are both Miraheze wikis whose page
  templates have nothing in common. Adding a source for a known site is one `SOURCES` entry; a new
  site is a parser module.
- **A source may publish more than one region's schedule.** Arknights' wiki lists CN and Global on
  every row, five months apart. Publish the one our readers are on and skip the row that lacks it —
  a CN date on a Global calendar is a confidently wrong date, not a near miss.
- **Game8 has no single template.** Seven shapes are known and a page may mix them: label/value
  detail tables, column tables, image-grid schedules (unsupportable), combined label+range+blurb
  cells, rowspan Start/End pairs, labelled `Start: … End: …` cells, and `<hr>`-separated date pairs.
  Full table in `docs/INGESTION.md`. Before assuming a new
  Game8 page will work, dump its structure and check **every** table — Endfield was written off as
  undatable on a pass that only inspected its `Duration` rows, and its real events were further
  down the page.
- **Check what fences a section off.** Inclusion is decided by headings, and the level varies: Persona
  5 hides fifty finished events behind nothing but an `<h4>Finished Events</h4>` in a collapsed
  accordion, while Genshin uses `h4` for sub-headings *inside* one event. So `h4` gates sections but
  never names one — an unrecognised `h4` must leave the current event title alone.
- **Prefer a source that states machine-readable times.** wiki.gg emits ISO timestamps with a timer
  per server region, which is the only reason `regionEnds` carries real data anywhere.
- **Silent drops are the dangerous failure.** A date format the parser does not recognise makes
  events vanish with no error. Abbreviated months (`Apr. 29 - May 13, 2026`) are supported for
  exactly this reason. When adding a source, compare the parser's event count against an
  independent count of the page.

## Event IDs are localStorage keys

```
`${game}:${slugify(title)}:${startsAt.slice(0, 10)}`
→ "genshin:mutual-aid-in-bloom-into-the-frostlands:2026-08-12"
```

Changing `slugify` or `eventId` in `src/shared/schema.ts` — including seemingly cosmetic changes to
the slug rules — **silently orphans every completion mark every user has, with no server-side
recovery**, because the server never had the data. If it must change, ship a client-side migration
that remaps old keys and keep it for at least a year. Use the **schema-guardian** agent on any such
change.

Two more key spaces have the same property, for the same reason:

- **`dailies:<game>`** (`dailiesId` in `src/shared/daily.ts`) keys a game's standing daily chore.
  Two segments, so it cannot collide with an event ID.
- **Game-day keys** (`dayKey`) are `YYYY-MM-DD` in *server-reset space*, not UTC — the day rolls at
  04:00 local server time. They are storage keys *and* they are compared with `<` and sorted, so the
  format is fixed. Changing the reset hour or the offsets moves every reader's streak by a day.
  A game whose server map differs lists the affected regions in `resetOffsets` (`games.ts`) —
  Endfield serves Europe off the Americas machine, so `europe` is UTC-5 there and its reset is
  09:00 UTC, not 03:00. Keep that override **per region**: a blanket per-game offset drags the
  regions that do have their own server onto someone else's clock.
  A game that rolls on a different *hour* says so in `resetHourLocal` instead — Reverse: 1999 resets
  at 05:00, not 04:00, so its day rolls at 10:00 UTC on its single UTC-5 server. Do not encode that
  as a bent `resetOffsets` value: shifting a game's stated server offset to land the right instant
  would misreport the server clock to everything else that asks for it. Both fields are absent for
  every game that takes the default, which is why adding the second one moved nobody's day keys. Every day-key function takes an
  optional `game` — **anything reading or writing a tick must pass it**, or it writes under one
  clock and reads under another. A day that drops out of `dailyDays` renders no pip, so a tick on it
  becomes unreachable; check real fixture windows before changing an offset.

The sanitizer at the ingest boundary recomputes an event ID only when a sanitized title actually
changed *and* the ID was minted the standard way. If a change to it starts moving IDs on real
fixtures, that is a data-loss bug, not a diff to regenerate.

## Scraping conduct

Sources are community wikis. Treat them as a guest would:

- Honor `robots.txt`; set a descriptive `User-Agent` with a contact URL.
- One request per source per refresh cycle, minimum 6 hours apart.
- **Space requests to one host**, honouring its `Crawl-delay` and defaulting to 2s. Eight of the
  fourteen sources are game8.co pages, so the per-source floor alone still permits one cycle to arrive
  as eight back-to-back requests to a single site — which is the shape an edge network throttles, and
  what a burst looks like from the far end regardless of our intent.
- Send `If-None-Match` / `If-Modified-Since`; treat `304` as "skip, unchanged".
- Cache raw snapshots so re-parsing never re-fetches. **Iterate against fixtures, not the network.**
- Record `sourceUrl` on every event and surface attribution in the UI.

Note that game8.co disallows `GPTBot` and `Google-Extended` in `robots.txt` — it has opted out of
AI-training crawlers. Our use is a low-rate personal aggregator with attribution and no model
training, and no `User-agent: *` rule applies to our paths. Keep it that way: do not raise the fetch
rate, and do not add an LLM that consumes page content.

**game8.co does not answer a GitHub Actions runner** (confirmed 2026-08-17). Its edge returns
`202 Accepted` with a bot-management body to every one of the eight game8 sources, from the first
scheduled cycle onward — `last confirmed: never` — while the same URLs return `200` and parse
cleanly from a normal address. So `robots.txt` permits us and the network does not, and those eight
games have only ever been built from checked-in fixtures in CI.

The per-host spacing above does not fix this and was not meant to: a 202 on the very first request
of a cycle is address reputation, not rate. **Do not work around it.** Browser-shaped headers, a
proxy, or a residential egress would each be defeating a deliberate access control, which is the
same reason `uma.moe` was declined below — and unlike `uma.moe` we would be doing it to a host whose
`robots.txt` was welcoming, which makes it worse, not better. The legitimate options are to run the
refresh from an address game8 will serve, or to find those games another source.

A source whose ToS forbids automated access does not get an adapter. Flag it and ask.

**Sources assessed and declined** (2026-08-17), so these are not re-litigated each pass:

| Source | Verdict |
|---|---|
| `azurlane.koumakan.jp` | **Declined.** `Content-Signal: ai-input=no` — an explicit refusal of collecting content as model input, which is what capturing a fixture to read amounts to. Stronger than game8's or wiki.gg's signal. Find Azur Lane another source |
| `uma.moe` | **Declined.** Data comes from an API behind a Cloudflare Turnstile proof header; an adapter would mean defeating a deliberate access control. The `robots.txt` is permissive, but the gate is not in `robots.txt` |
| `reverse1999.fandom.com` | **Built** (2026-08-17), via `api.php`, not the wiki page — see § Fandom below |
| `bluearchive.fandom.com` | **Declined.** Fetches and parses fine; the page is the problem. Its `Event/Event_List` is a JP-server archive whose newest entry ended 2026-02-18, so all 88 rows are history and it yields **zero** live or upcoming events. An adapter would put an empty lane on the calendar and, because the runner rejects a body that parses to nothing, report a broken source forever. Same failure as the Infinity Nikki Game8 page, further along |
| `bluearchive.wiki` | **Built** (2026-08-17), from the rendered `/wiki/Events` page — see § Blue Archive below |
| `holodori.wiki` | **Built** (2026-08-18), from the rendered `/wiki/Events` page. Miraheze again, so the same call as Blue Archive; CC BY-SA 4.0, no `Content-Signal`, no `Crawl-delay` for `*` |
| `prydwen.gg`, `gametora.com` | **Cleared, unbuilt.** `User-agent: *` allows the paths we would want. prydwen sets `Crawl-delay: 10`, far below our one-per-6h |

`.github/ISSUE_TEMPLATE/feature_request.yml` points readers at that table by heading, so a source
request can be checked against it before anyone writes it up — the loudest feedback on the first
release was "not enough games" (`docs/FEEDBACK.md`), which makes this the request that arrives most.
Keep the heading if the section moves.

wiki.gg hosts (`arknights`, `endfield`) carry `Content-Signal: search=yes, ai-train=no, use=reference`
with `Allow: /`, and disallow `ClaudeBot` and other AI crawlers by name. Our fetcher is neither: it
trains nothing, and no LLM reads the page content — constraint 2 is what keeps that true, so it is
load-bearing here and not only a cost decision. Note also that Reverse: 1999, Blue Archive,
Umamusume and Nikke have **no wiki.gg wiki** — those subdomains 401.

**Fandom: read the API, never the page.** `reverse1999.fandom.com/wiki/Events` answers a non-browser
client with a Cloudflare managed challenge — HTTP 403, `Just a moment…`, "Enable JavaScript" — and so
does `/robots.txt` itself, from a datacenter address. Browser-shaped headers or a JS-executing client
would get past both and **must not be used**: that is defeating a deliberate access control, the same
reason `uma.moe` was declined above.

What makes this source legitimate anyway is that the wiki publishes a second, sanctioned surface. Its
`robots.txt` — read in a browser, where it serves fine — has no `Disallow: /` for `*` and explicitly
**allows** `/api.php?action=`, and that endpoint answers our real `User-Agent` with a `200` and a JSON
body. So the adapter fetches `api.php?action=parse&page=Events`, with no impersonation anywhere: our
own headers, on a path the site put in writing. The only namespaces `*` is refused are `Special:`,
`User:`, `Template:` and `Help:`, none of which we want; `parsers/fandom.ts` skips `Special:` links
for that reason.

One consequence to keep in mind: because `/robots.txt` is unreadable from a challenged address, the
robots gate **fails closed there and the source is skipped**. That is a warning line rather than a
broken build — `skipped_robots` does not touch the failure streak, and the run only hard-fails if
*every* source is blocked — so the scheduled refresh simply never updates this game, and the feed
falls back to the checked-in fixture. Refreshing it means running `bun run refresh` from an address
Fandom serves, which is how its first snapshot was taken.

**Blue Archive: the page, never the API — the opposite call to Fandom.** `bluearchive.wiki` is a
Miraheze wiki, and Miraheze's `robots.txt` **disallows** `/w/` and `/*?action=`. So the route
`parsers/fandom.ts` takes is the one that is closed here, and the rendered `/wiki/Events` page is the
surface `*` is allowed — it answers our own `User-Agent` with a `200`, no `Content-Signal`, and no
`Crawl-delay` for us. `Special:` is disallowed too, which is why `parsers/bawiki.ts` skips those links
exactly as the Fandom one does.

Three things about that page are worth knowing before touching it, all of them ways to publish a
confidently wrong date:

- **It states JP and Global in separate tabs, and the Japanese one runs four to nine months ahead.**
  Same hazard as the CN column on `akwiki`, same answer: publish Global only. The tab's *nav button*
  carries the id `tabber-Global_version-label` and sits above **both** panels, so a reader that slices
  from the first id match reads the Japanese schedule while believing it read ours.
- **There are three Global tabs, not one** — the schedule, plus Mini-Event and Joint Firing Drill
  further down, whose ids are the same name with `_2` and `_3`. The parser finds the schedule by its
  `Name (EN)` header rather than by position, and `canParse` asserts that lookup, so a renamed tab or
  column fails the run instead of quietly emptying the lane.
- **The page states no time of day and no timezone anywhere.** The schedule's dates are bare
  `YYYY-MM-DD`, which is honest day precision. Its five other tables (Mini-Event, Reward campaigns,
  Attendance bonuses, Guide missions, Joint Firing Drill) *do* carry a wall clock — `08/12/2026 11:00`
  — but name no zone for it, and three of the five do not say which server they describe. Those are
  deliberately unparsed: reading them as UTC invents the fact that matters, and rounding to a day does
  not save it, because a 04:00 local boundary lands either side of UTC midnight depending on the
  offset assumed and the start's day is part of the event ID. Attendance bonuses would be a real
  dailies source if a zone is ever stated. For the same reason `ba` has no `resetOffsets`: Blue
  Archive Global does run one worldwide server, but nothing in this source says on what clock.

**hololive Dreams: the same Miraheze call as Blue Archive, and the opposite data.** `holodori.wiki`
is Miraheze too, so `/wiki/Events` is the surface `*` is allowed and `/w/` and `?action=` are closed
— `parsers/holodori.ts` takes the route `bawiki.ts` takes, for the reason it takes it. What differs
is the quality of what is there, and three things are worth knowing:

- **It states its timezone on every cell.** Every boundary is `08/17/2026 8:00PM (JST)`, which makes
  this the only wiki source here publishing `exact` precision on both sides without a per-region
  timer. `parseSlashClockZone` **requires** the zone rather than defaulting to UTC, so a row that
  ever loses it drops out instead of landing nine hours off. That is also where `holodori`'s
  `resetOffsets` of UTC+9 comes from — evidenced, not assumed; see docs/DATA-MODEL.md.
- **Inclusion is fenced by an `<h2>`, and the two tables are identical.** `Current Events` and
  `Past Events` have the same columns, so a reader that took every `wikitable` would put the back
  catalogue on the calendar with nothing to mark it. Rows are checked against `ctx.now` on top of
  the heading, because "Current" is maintained by hand and goes stale before anyone moves a row.
- **Every event title is still a red link.** The wiki has no article for any of them yet, so each
  links to `?action=edit&redlink=1` — a create-page form, and a `?action=` URL this wiki's
  robots.txt disallows. The parser refuses a href with a query and falls back to the events page;
  when the articles exist, they get linked with no change.

Two rows on the page are not events and are meant to be missing. `Beginner Mission` runs
`Game Launch` → `Unknown`: no start means no event ID, and a permanent tutorial chore is not what a
calendar of deadlines is for. An `Unknown` **end** is kept, though — that is `endsAt: null`, and
unlike `bawiki.ts` this parser does not drop a started-but-undated row, because the heading has
already said the event is running.

`scripts/refresh-sources.ts` enforces all of the above in code — the 6h floor, one request, no
retries, conditional headers, per-host spacing, robots (failing closed when `robots.txt` cannot be
read). Anything that would make it fetch more often is a change to this section first.

**A source down is a warning; a source down for days is a broken build.** One wiki failing must
never blank a calendar or stop the sources that did answer from being committed — so a failure is
exit 0 and the previous snapshot stands. But a source that has failed `BROKEN_AFTER_FAILURES` (3)
cycles running is not having a bad afternoon: that game's calendar has been quietly built from a
checked-in fixture for a day and a half. The runner reports those as `broken` — a GitHub annotation,
a row in the job summary with the status code, and a `broken` step output — and `refresh.yml` fails
the run on it in a **final** step, after the commit and the CI dispatch. Exiting non-zero from the
runner instead would skip the commit and throw away the pages that did arrive. This tier exists
because six of seven sources failed every cycle for three days behind a green tick; a warning nobody
opens the log to read is not a signal.

## Untrusted input

Every string on an event came from a page we do not control. `src/ingest/sanitize.ts` is the trust
boundary and it is wired into `toAdapter()` in `src/ingest/adapters/index.ts`, which is the single
seam every source passes through — **do not sanitize inside a parser**, and do not add a code path
that reaches `parser.parse` directly. Parsers stay pure readers of one site's markup.

The sanitizer never touches a date, cleans rather than drops (a title that sanitizes to nothing is
the only drop), and logs every repair and drop by default. See `docs/INGESTION.md` § Stage 2.5.

## Events that repeat daily

Some events are twenty small jobs on twenty deadlines, not one job with an end date, and a missed
day is unrecoverable. `src/shared/daily.ts` decides dailiness from what the source published —
`type: "login"`, or "daily"/"check-in"/"7-day" wording — and never from a game's habits or an
event's length. It adds **no schema field**, so the feed contract is untouched.

- The day rolls at **04:00 server time** (`RESET_HOUR_LOCAL`), per region. Getting this wrong ticks
  the wrong box for four hours every night.
- **An unannounced end yields no checklist**, not a checklist of guessed length — the `endsAt: null`
  rule applies here exactly as it does to a countdown.
- **A tick is never removed except by the reader**, including ticks outside the window the feed now
  claims. A source quietly moving a date must not erase a fortnight's streak that exists nowhere
  else.
- **A repeating event the reader marked done leaves the strip.** They have said there is nothing
  left to do; keeping a tickable chip for it is the app arguing with them. Their logged days are
  untouched, so unmarking it brings the chip and the streak straight back.
- **Detection is a guess, not a verdict — and it ships off.** `prefs.detectDaily` defaults to
  `false` and the control is labelled experimental: wording is a weak signal and gets it wrong in
  both directions, so a new reader opts in rather than out. The default moves nothing for an
  existing reader, whose stored `prefs` wins. The reader can mark any event as repeating, or unmark
  one detection got wrong (`progress.daily`, resolved by `resolveDaily`), whether the guessing is
  on or off. Store an override only when it *disagrees* with detection —
  recording agreement would freeze today's guess and stop a better parser from ever reaching that
  event. Neither control ever deletes a mark or a logged day, so both are reversible.

## Events the reader entered themselves

No adapter list covers a ten-game player, so a reader can define a game and type in events
(PRD F13, `src/shared/custom.ts`, `src/client/state/useCustom.ts`). They join the same lists,
timeline, sort, filters, progress, ignore and daily stores as scraped events. Four rules:

- **Their ids live in their own spaces**: `mygame:<slug>` and `myevent:<random>`. Never
  `${game}:${slug}:${date}` — a reader can type a scraped event's exact title and date, and that
  collision would silently share one completion mark and one streak between two events. Random also
  means renaming their own event never moves its id. `dailies`, `mygame` and `myevent` are reserved
  first segments and **none may ever become a `GameId`**; a test pins this.
- **Nothing they type enters the ingest pipeline.** `sanitize.ts` and `merge.ts` are for pages we do
  not control. Their events are not fetched, parsed, merged, scored or quarantined.
- **A hand-entered date is never attributed to a source.** No `sourceUrl`, no source link, and the
  row and detail sheet both say it is theirs. `"I don't know when it ends"` is an offered answer, for
  the same reason the parsers are forbidden from guessing one.
- **They are in the export.** These exist in one browser and nowhere else, so an export without them
  is a lossy backup. Import merges by id and never removes.

A lane may now be a game the reader invented, so `gameMeta` is a context resolver (`metaFor`, pure
and total) rather than a direct lookup — a lane can outlive its game when an import carries an event
whose game did not come with it.

## Shipping a new version

The shell is cached cache-first, so a reader with the tab open keeps the bundle they first loaded.
An old app presented as current is the same failure as old events presented as current, so a waiting
version is disclosed and reloaded on a tap (PRD F14, `docs/ARCHITECTURE.md` § Shipping a new version
to an open page). Four things hold it up:

- **`sw.js` must not `skipWaiting()` on install.** It activates only on the `skip-waiting` message
  the reader's tap sends. Claiming an open page unasked runs the old bundle against the new cache and
  says nothing.
- **`__BUILD__` must stay in `sw.js`.** `scripts/build-static.ts` substitutes a hash of the built
  shell for it, which is what makes a deploy's worker bytes differ and therefore detectable. It
  throws if the placeholder is gone — do not "fix" that by dropping the substitution. There is no
  `CACHE_VERSION` bump ritual any more; the cache name is a namespace, and per-build names would
  discard the stored feed an offline reader is reading.
- **The feed is not part of the build id.** It changes twice a day and needs no reload; announcing it
  as a new version teaches readers to dismiss the notice unread.
- **The app never reloads itself.** Someone may be mid-way through typing an event in.

## Conventions

- **Commit straight to `main`.** This is a solo repo and its history is a single line; do not open a
  branch for a change unless asked for one. Committing still waits to be asked.
- **Only ever commit your own work.** Stage the files you changed, by path, and nothing else. The
  working tree may already hold edits, untracked fixtures or a half-finished experiment that someone
  else — the user, or another agent — put there and has not decided about yet; `git add -A`, `git
  commit -a` and `git stash` all sweep those into your change or out of sight. Authorship in the log
  then says you wrote something you never read, and the commit stops being the one coherent change
  the bullet below asks for. If unrelated changes are in the way, say what you see and leave them
  alone.
- **Commits are self-contained and succinct.** One coherent change per commit, typechecking and
  passing tests on its own — a feature spanning layers splits as model → store → UI → docs, each
  step green by itself, even when that means widening a type in the model commit that only the UI
  commit uses. `docs/FEEDBACK.md` makes the same argument for adapters specifically: do not batch
  six games into one commit, because each one is a fixture and a test that has to prove itself.
  Succinct is about the message, not the change: a one-line subject in plain English, and a body
  that says *why* — the reasoning a diff cannot show — rather than listing the files it touched.
  Never reformat code the change did not touch; a formatter the project does not run buries a
  100-line change in a 550-line diff.
- **Zod schemas are the single source of truth for types.** Derive with `z.infer<>`; never
  hand-write an interface that duplicates a schema.
- Every adapter ships a fixture in `fixtures/<game>/` and a test asserting parsed output. This is
  how a source silently changing shape gets caught.
- Keep old fixtures when a source changes shape — the old one is the regression test proving the
  parser still handles the previous format. Fixtures are pinned and permanent; `snapshots/` is the
  current page and gets overwritten. Do not conflate them.
- **The page is two columns past `lg`, and the split is the one below.** What the page *tells* the
  reader to do — the next deadlines, tonight's dailies — pins to a rail on the left and stays put
  while the lists it *shows* them scroll beside it. Below that breakpoint it is one column in the
  same order. The rail's rule belongs to the panel, not the column: the panel is short and the list
  is long, so a full-height divider would spend most of its length walling off a gap.
- **Truncating a list is not re-sorting it.** Each section shows `LIST_CAP` rows and offers "show
  all N". The rows below the cut keep their place in the order, stay counted in the header, and stay
  on the timeline — so the *sorting groups, it never reorders* rule below holds for what is hidden
  exactly as it does for what is shown. Expanding is per-visit state, not a stored preference: it is
  something a reader does while reading one list, not a statement about how the app should work.
- **A game we add arrives switched off, and `knownGames` absent means *unrecorded*.** Adding a
  source is our decision; a reader who plays two games did not ask for the other twelve. So a lane
  missing from `prefs.knownGames` is new *to them* and is hidden on sight (`adoptNewLanes`, PRD F8).
  The trap is the other reading: every install from before this existed has no `knownGames` at all,
  and treating that as "has been offered nothing" switches off every game they already read. Seeding
  records what is on their screen and changes nothing else. Lanes they invented (`mygame:`) are
  recorded but never hidden.
- **Which view opens is the reader's answer.** `prefs.view` is asked once on the first run (PRD F8)
  and written by the tabs from then on. It was component state, which meant a reader who preferred
  the timeline was put back on the list by every reload, with nothing to blame but the app
  forgetting. The stored answer is theirs; do not add a heuristic that overrides it.
- **A list row is one target.** The event row opens the event and does nothing else — status,
  effort, notes and the daily checklist all live in the detail sheet. A second control inside a
  full-bleed row target is a mis-tap waiting to happen, and a decorative chevron says "this opens"
  without adding a second stop for keyboard and screen-reader users.
- **Sorting groups, it never reorders within a group.** Every mode falls back to
  `endingSoonestFirst`, so choosing one can never cost the reader the deadline order the product
  exists for.
- **Telling the reader to do something is not the same as showing it to them.** `showCompleted` and
  `showIgnored` decide what they can *look at*; the "next to expire" headline and the dailies strip
  are *instructions*, so both drop anything done or ignored regardless (`outstanding` in
  `src/client/state/lens.ts`). Being pointed at a job you already finished is the bug either way.
  For the same reason "next to expire" reads the minimum end date rather than the head of the list,
  which under "doing first" is a different event entirely.
- **The page states its own age unprompted, and reads it off the data.** The footer says when event
  data last refreshed on every load, not only past the two-day threshold — a page silent about its age
  reads as current, and "how old is this?" has to be answerable before a countdown is worth trusting
  (PRD F7). `freshness()` in `src/shared/feed.ts` is the one definition: it takes the newest
  `lastSuccessAt` and **never `generatedAt`**, which is a build stamp that would call a
  fixture-backed calendar minutes old, and it treats a game as only as fresh as its *oldest* source,
  so one live wiki cannot vouch for a stalled sibling. Given that eight sources cannot be fetched
  from CI at all (§ Scraping conduct), this disclosure is the only thing standing between a reader and
  a confidently stale calendar — do not let a future change source it from the build clock.