fix: isolate resource execution and subscriber publication

[smiggleworth]

A resource subscriber exception could stop remaining notifications or be mistaken for an async loader failure. Abort handlers, pending subscribers, synchronous loaders, and error coercion could refresh or dispose the resource while the superseded execution continued publishing.

Each execution now establishes controller ownership before abort callbacks and validates that ownership after callback boundaries. Sync values and errors receive the same freshness checks as async completions. Promise rejection handling is separated from success publication; subscriber and logger failures cannot interrupt delivery. Thenable inspection and Promise assimilation failures use the loader error contract. Error normalization completes before publication eligibility is rechecked, and coercion failures settle without escaping the promise handler.

Thirteen new regressions cover notification isolation, logger failures, sync reentry, pending disposal, abort-handler refresh, self-abort, thenable inspection, promise assimilation, and error coercion. TDD established seven initial failures, an additional throwing-getter failure, and three review regressions before their fixes. The existing successful thenable test remains green.

Validation at bdb62d8, rebased onto merged root and query fixes: 14 focused tests, format, lint/typecheck, build, 336 unit / 60 repository / 1632 DOM / 53 browser tests, public types, and 21 packed-consumer tests pass. The unchanged 256 KiB hydration bundle limit passes.

The existing resource-named tier-2 benchmark exercises createQuery rather than ResourceCell. It provides adjacent cancellation coverage and does not establish resource performance improvements.