…ype gymnastics)

Add `type-fest` as a dev dependency and use two of its helpers in place of
hand-written equivalents:

- `Entries<T>` replaces the `Object.entries(x) as [K, V][]` tuple assertions
  in `lifecycle.ts` and `tab-tracker.ts`. The entry shape is now derived from
  the source type (`Required<RuleCountMap>` keeps the value `number`, matching
  the cross-frame sum), so it can't silently drift from the map it iterates.
- `IsEqual<A, B>` replaces the bidirectional `AssertExtends` drift guard in
  `message-schemas.ts`, collapsing the two-direction parity check into one
  structural-equality assertion between the zod inference and the wire type.

Type-only changes; `bun run check`, tsc, and the affected test suites pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

…eRecord

`type-fest` has no `FromEntries` helper, so the four `Object.fromEntries(...) as
T` casts can't be typed off-the-shelf. Two of them build the same shape —
`Record<RuleId, boolean>` (`RuleStates`) — so introduce a small `buildRuleRecord`
helper in `rule-metadata.ts` (next to `RULE_IDS`, the canonical id list) and
route those two through it:

- `storage.ts` DEFAULT_STATES
- `rule-engine.ts` ALL_DISABLED

The single unavoidable `as` (the `string`-key widening of `Object.fromEntries`)
now lives once inside the helper. Call sites become cast-free, key coverage is
guaranteed by `RULE_IDS`, and the value type is inferred + checked against the
annotated target rather than asserted.

The other two fromEntries sites are intentionally left as-is: `availability.ts`
builds its map async over `RULES` (needs the rule object, not just the id) and
`rule-options.ts` produces the non-uniform `RuleOptions` shape — neither fits a
`Record<RuleId, V>` builder.

`bun run check`, tsc, and the affected suites (storage / rule-engine /
rule-metadata / catalog) pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

`parse-config.test.ts` mocks `rules/rule-metadata` with a factory, and
`storage.ts` (pulled in transitively) now calls `buildRuleRecord` at
module-init to build its default state. The mock didn't export the helper, so
the suite failed to load with `buildRuleRecord is not a function` — only when
the full suite runs together (targeted runs that excluded this file passed).

Add a stub `buildRuleRecord` to the mock factory that mirrors the real helper
over the small mocked id set.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>