Event log integrity (sole source of truth):
- SqliteEventStore: serialize append/appendAll under a Mutex, enable WAL +
busy_timeout + synchronous=NORMAL, roll back on any Throwable. Replaces the
app-computed `SELECT MAX(seq)+1` read-modify-write that dropped events under
concurrent appends (race was invisible to CI: only the in-memory store and
single-threaded :memory: tests were ever exercised).
- Serialization: encodeDefaults + ignoreUnknownKeys, explicit @SerialName on all
46 EventPayload subclasses and event-referenced enum constants, @Serializable on
RiskLevel/RiskAction. Guards the append-only log against silent corruption from
future class renames, field removals, or default-value changes.
Approval/grant security (Invariant: approvals cannot widen authority):
- Tier authorization is now a ceiling (request.tier.level <= max granted) instead
of set membership; SESSION grants bind to a specific toolName instead of matching
everything; handleCreateGrant rejects empty/over-tier/scopeless grants.
Router chat wiring (Phase 0-2): ChatInput round-trip, StartChatSession from IDLE,
router-panel layout, workflows behind Ctrl+W.
Tests: SqliteEventStore concurrency, serialization round-trip + discriminator
stability + unknown-key tolerance, adversarial grant scope/tier; updated existing
approval and reducer tests for the new grant semantics and StartChatSession effect.