perf: performance improvements 1

agents-docs/features/messaging.md

@@ -95,8 +95,9 @@ Rules (`message-sync.rules.ts`, `message-integrity.rules.ts`):
 
 - Merges are **additive** — sparser peers never wipe richer local history.
 - `findMissingIds` compares remote inventory to local `revision` / `headHash` (and legacy `ts` / `rc` / `ac`).
-- `INVENTORY_LIMIT` = 1_000_000 (safety ceiling for pathological rooms).
+- `INVENTORY_LIMIT` = `FULL_SYNC_LIMIT` = **20_000** (2026-07-14, RAM investigation; previously 1_000_000). Building an inventory or full-sync batch loads full message rows into memory, so the ceiling must stay bounded. Only the most recent 20k messages per room are reconciled peer-to-peer; older messages stay local-only. `ACCOUNT_SYNC_MESSAGE_LIMIT` follows `FULL_SYNC_LIMIT`.
 - Sync polling: 10 s when catching up, 15 min after a clean cycle (`SYNC_POLL_FAST_MS` / `SYNC_POLL_SLOW_MS`).
+- NgRx store retention: on room switch, inactive rooms are pruned to the most recent `CACHED_INACTIVE_ROOM_MESSAGE_LIMIT` = **100** messages each (`messages.reducer.ts`), keeping return-visit rendering instant while bounding store growth across many rooms. The active room is never pruned; the local DB keeps full history.
 
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@@ -204,6 +205,7 @@ Deletes keep tombstone semantics (`isDeleted`, empty `content`) so inventory syn
 
 | Date | Change |
 |------|--------|
+| 2026-07-14 | RAM bounds: `INVENTORY_LIMIT`/`FULL_SYNC_LIMIT` lowered to 20k (most recent messages reconcile); NgRx prunes inactive rooms to 100 cached messages on room switch |
 | 2026-07-13 | Incoming DMs raise system notifications through the notifications domain (previously unread-badge only) |
 | 2026-07-13 | Recipient matching for DM and `direct-call` events must span all local identity aliases (provisioned actor ids included) |
 | 2026-07-05 | Initial comprehensive messaging contract (replaces thin direct-messaging summary) |