docs: bilingual counterparts for the projection READMEs; review-driven RFC precision

New zh pairs for the session-projection group and package READMEs (both gained their missing language-switcher lines); the packages/README rows, apiproxy README, and tool-todo README zh sides catch up with their edited English; the group README's stale ProjectionProvider name becomes ProjectionDefinition. RFC precision from review: asOfSeq is the last event's seq (session.seq - 1, -1 empty; subscribed.lastSeq vocabulary) and a new risk names the accepted dev-only staleness window when registry churn changes the key set mid-session. Pairing re-recorded; 540 pairs consistent.
2026-07-28 01:19:30 +08:00
parent c10edbbc85
commit 4d7b30ab72
15 changed files with 98 additions and 18 deletions
@@ -64,7 +64,7 @@ declare module 'cordis' {
  projections?: { asOfSeq: number, values: Partial<SessionProjectionMap> } }
 ```

-The api-proxy history handler, after slicing the tail page, reads `session.seq`, then synchronously walks the registry — no `await` anywhere, so every key's value and `asOfSeq` form one consistent cut, and `asOfSeq` equals the window tail seq. Api-proxy holds zero domain knowledge (the same carrier/contributor relationship as `viewFor` against `ctx.tools`).
+The api-proxy history handler, after slicing the tail page, synchronously walks the registry — no `await` anywhere, so every key's value and `asOfSeq` form one consistent cut. `asOfSeq` is the **last event's seq** (`session.seq - 1`; `-1` for an empty log, the same vocabulary as `session/subscribed.lastSeq`), so a push frame carrying the first post-baseline change always compares strictly greater. Api-proxy holds zero domain knowledge (the same carrier/contributor relationship as `viewFor` against `ctx.tools`).

 No new RPC method. The timing coincidence is exact: every moment the client needs a fresh baseline (open, reconnect resync, gap repair) already pulls the tail page, and the only path that never needs one (loadOlder) is the only path that passes `beforeSeq`. The client therefore has **no** independent "refetch the baseline" decision at all. Window content is never a signal: "no domain event in the window" is unanswerable there by construction, and only the baseline answers it.

@@ -176,6 +176,7 @@ Infrastructure first; the three in-flight PRs are left untouched and re-target a

 - **Whole-value rule is load-bearing**: a future domain logging bare deltas cannot serve consumers from its latest event and complicates its own unit. Mitigation: the rule is stated here and in the projection package README; the unit contract makes the full state explicit at every transition.
 - **Synchronous unit discipline**: `init`/`apply`/`view` that await would tear the consistency cut. The registry documents and the invariant companion asserts synchronicity as far as practical; review owns the rest.
+- **Live registry churn is not pushed**: loading or unloading a domain plugin mid-session changes the key set, but no session event fires and no frame is pushed; open clients hold the stale key until the next tail pull (reconnect, gap repair, open). Accepted as a dev-only (HMR) staleness window — a registry-change push can be added to the change feed later without contract impact.
 - **Eager drive costs on busy sessions**: every committed event passes every registered unit's `apply`. Units are cheap per-event by construction (whole-value rule), non-matching events return the same reference, and the count of registered domains is small; if a hot path ever shows, per-unit event-type prefilters can be added without contract change.
 - **Projection payload growth**: every tail page carries every registered key. Payloads are whole values of UI-scale state (a todo list, a goal snapshot); if a future domain's value is large, per-key opt-out or lazy keys can be added to the request without changing the model.
 - **Command log volume**: two log-only events per slash command; bounded by human command frequency, negligible against chunk volume.