Merge remote-tracking branch 'origin/master' into session-query-trace

# Conflicts:
#	packages/session-query/session-query/README.md
#	packages/support/invariants/src/index.ts

packages/support/invariants/README.md

@@ -1,8 +1,8 @@
 # dsh-invariants
 
-Dev-mode event-contract assertions. This pure-listener plugin checks relationships among session events, agent states, scoped dispatches, and model requests at runtime; it does not own or change product behavior.
+Runtime event-contract assertions intended for development diagnostics. This pure-listener plugin checks relationships among session events, agent states, scoped dispatches, and model requests; it does not own or change product behavior.
 
-**Off in production.** Enable it in tests and the demos, where a contract violation should fail loudly. It costs nothing when not registered, and doubles as executable documentation of the event taxonomy — the assertions *are* the contract.
+The plugin has no environment guard: it is active wherever it is registered. The default [`dsh-agent-core`](../../core/agent-core/README.md) bundle mounts it unconditionally; a custom composition can omit it when the runtime cost is undesirable. It doubles as executable documentation of the event taxonomy — the assertions *are* the contract.
 
 Session itself owns immutable, surface-valid log storage in every composition: it takes one lossless JSON snapshot of each candidate, validates the complete surface transition, deep-freezes the accepted record, and exposes the log through immutable array snapshots. The invariants plugin checks the remaining cross-record and cross-seam rules that Session does not own.
 
@@ -45,8 +45,17 @@ On any violation it throws `InvariantError` (`code: 'INVARIANT'`).
 
 ## Why runtime assertions remain useful
 
-Session enforces the per-record storage boundary at runtime, where a cast cannot bypass it. Pervasive `DeepReadonly<SessionEvent>` types would add noise across consumers without expressing relationships such as turn/step nesting, subject-correct scoped dispatch, or equality between a request and its log reconstruction. This plugin checks those relationships in development while `dsh-session` keeps history immutable in every composition. See [source-owned session immutability and dev-mode invariants](../../../docs/rfc/implemented/architecture/2026-06-11-dev-invariants-over-deep-readonly.md).
+Session enforces the per-record storage boundary at runtime, where a cast cannot bypass it. Pervasive `DeepReadonly<SessionEvent>` types would add noise across consumers without expressing relationships such as turn/step nesting, subject-correct scoped dispatch, or equality between a request and its log reconstruction. This plugin checks those relationships wherever it is mounted while `dsh-session` keeps history immutable in every composition. See [source-owned session immutability and dev-mode invariants](../../../docs/rfc/implemented/architecture/2026-06-11-dev-invariants-over-deep-readonly.md).
 
 ## Seeded sessions
 
 A seeded or forked session arrives with events already in its log because construction does not emit `session/event` for each seed record. `Session` validates, snapshots, and freezes every seed record before accepting it; on `session/created`, this plugin replays the accepted log only to rebuild and check its relational trace state.
+
+## Model Experience
+
+None, as this observer only validates events and frozen requests and never rewrites prompts, schemas, messages, or streams.
+
+## Known Limitations and Deferred Work
+
+- **The request-reconstructability assertion covers loop-built requests only** — hand-built one-shots (e.g. compaction's summarize call) carry no live `sessionId` marker and are skipped.
+- **Merge-extended event families get no family-specific assertions** — `compact/*` lock pairing and `hook/*` invoked/result pairing are not checked here; only the core turn/step/chunk/tool-result contract is.

packages/support/invariants/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@deepseek-ai/dsh-invariants",
-  "description": "Dev-mode event-contract assertions for the DeepSeek Harness",
+  "description": "Runtime event-contract assertions for DeepSeek Harness development diagnostics",
   "version": "0.0.1",
   "private": true,
   "type": "module",

packages/support/invariants/src/index.ts

@@ -1,12 +1,15 @@
 /**
- * Dev-mode invariants: a pure-listener plugin that asserts relationships in
- * the harness event contract at runtime.
+ * Runtime invariants: a pure-listener plugin that asserts relationships in
+ * the harness event contract. It is intended for development diagnostics but
+ * has no environment guard, so it is active in every composition that mounts
+ * it (including the default `dsh-agent-core` bundle).
  *
  * Everything is a plugin — this is just listeners on `session/created`,
  * `session/event`, `agent/status`, and the scoped dispatch and request seams.
- * It is **off in production**: enable it in tests and demos, where a contract
- * violation should be a loud failure rather than a subtle one. It doubles as
- * executable documentation of the relational event taxonomy.
+ * Custom compositions can omit it when the runtime assertion cost is
+ * undesirable. When mounted, a contract violation is a loud failure rather
+ * than a subtle one. It doubles as executable documentation of the event
+ * taxonomy: the assertions below are the contract.
  *
  * Session owns immutable, surface-valid log storage: it validates, snapshots,
  * and deep-freezes every accepted event at the source. This plugin checks the
@@ -249,7 +252,7 @@ function checkTransition(from: AgentStatus | undefined, to: AgentStatus): void {
 }
 
 /**
- * Register the dev-mode invariants. Contributions are effect-scoped, so
+ * Register the runtime invariants. Contributions are effect-scoped, so
  * disposing the plugin fiber removes all listeners (HMR-safe). On (re-)apply
  * the trace state is rebuilt by replaying each existing session's log, so a
  * hot reload mid-turn does not falsely reject the next event.