Versioned data fetches, data carried across worker releases, plain load failure, comboRows by rowGain, nextBottles memo, generator id guard

[cjimti]

Data (#109)

app.js fetches the four data files with ?v=<versionLabel> (dev unstamped) and refuses a response that is not ok. A load failure sets #loading to "The menu did not load. Check the connection and reload." with no exception text.

sw.js fetches data with cache: 'no-cache', stores and matches it on origin plus path, and in activate copies data entries from the stale caches into the new one (carryData, copyData) before deleting them. A failed copy is caught and does not fail activation.

check_assets.check_data fails on an unversioned data fetch, data keyed on the query, or a cache delete without the carry. CLAUDE.md describes the rules.

Engine (#117)

• openSharedLink calls selectMenu('shared'); the gate flags are written only in selectMenu and emptyFilter.
• comboRows scores each set with rowGain, so a stand-in is counted. subsetOf is removed.
• nextBottles is memoised on the shelf code (rankNext does the work). Scoring by rowGain took comboRows from about 2.5 ms to about 9 ms on a near-empty shelf in node, and the Menu rail asks on every repaint. The gains memo comment carries the timings.
• loadHave drops ids not in the bar, so boot's save removes them from the store.

Generators (#117)

llms.refuse_unsafe_ids stops pages.py and cards.py on a drink id that is not a slug and names it. pages.py removes the empty drink/<id>/ folder an orphan page leaves. test_checks.py adds 11 cases (245 to 256).

Checked

• make verify passes.
• Node harness over app.js: on 57 shelves (empty, gin, every starter shelf, every single bottle) the Next rows are identical to main and every +N equals unlockedBy. A store of {"gin":true,"nothing-such":true} is saved back as {"gin":true}.
• Node simulation of sw.js with a mock Cache API: data served offline after two releases, requested with no-cache, and activation completes when the copy throws.
• Scratchpad copy of the repo: an id of ../x is refused by both generators with nothing written; an orphan page's folder is removed.
• Chrome on localhost:8010: data requested as ?v=dev, ?s=3 opens on Shared menu, a 404 on cocktails.json and a rejected fetch both show the sentence, the unknown id is dropped from the store, Next rows render on the Bar tab and the rail for a gin shelf.

Not checked

• A real service worker (https only), so the carry across a release and offline load are verified only in simulation.
• A 304 and ?v=v1.x.y in the network panel on the live site after a tag.
• 390px, light mode and print; no rendering or CSS changed.

A tab still on an older release drops ids only a newer release knows, and its next tick saves the shelf without them.

Closes #109. Closes #117.