Merge remote-tracking branch 'origin/codex/invariant-service-seam' into codex/invariant-package-registration-gate

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-19-package-owned-invariant-service.i18n.yaml
#	docs/core-data-structures/session.md
#	docs/module-graph.md
#	package.json
#	packages/sdk/scripts/tsconfig.json

packages/bash/bash-sandbox/README.md

@@ -16,7 +16,7 @@ Semantics:
 
 - **Denials are result facts.** A failed run whose stderr carries the selected backend's own denial dialect — the signatures the provider stamps on every wrap (EROFS text under bwrap, EACCES under Landlock, EPERM under Seatbelt) — is reported as `BashRunResult.sandbox.denied: true` (conservative classification, read from the collected stderr tail); every CONFINED run also carries the mode it executed under (`result.sandbox.mode`) and the provider's enforcement completeness (`result.sandbox.enforcement`: `full`, or `partial` on an older Landlock ABI).
 - **Runner failures are sandbox failures, never command failures.** Foreground execution throws `SANDBOX_UNAVAILABLE`; a settled background process stamps `process.sandbox.runnerFailed`, which the bash producer renders through generic `task_output`. Spawn failures also pass through settlement, so confined background handles retain their mode/enforcement facts and release per-process accounting.
-- **Config-time default, per-call policy.** The DEFAULT mode is fixed by this entry's config for the executor's lifetime; `resolve()` stamps it onto every spec, and an explicit request-level `sandboxMode` override — set by the tool layer only for a call whose wider mode a human granted through `ctx.approval` ([the sandbox RFC § Escalation](../../../docs/rfc/implemented/feature/2026-07-06-sandbox.md)) — makes THAT call run, classify, and report under its own mode while every neighbor keeps the default (background facts are stamped per task at settle). The capability fact `ctx.bash.sandboxMode` reports the configured default so the tool layer advertises escalation only when this executor is mounted. The model learns of the sandbox only through result facts — the static bash tool description explains the denial marker; there is no current-mode statement in the system prompt.
+- **Config-time default, per-call policy.** The DEFAULT mode is fixed by this entry's config for the executor's lifetime; `resolve()` stamps it onto every spec, and an explicit request-level `sandboxMode` override — set by the tool layer only for a call whose wider mode a human granted through `ctx.approval` ([the sandbox Agent Note § Escalation](../../../.agents/notes/implemented/feature/2026-07-06-sandbox.md)) — makes THAT call run, classify, and report under its own mode while every neighbor keeps the default (background facts are stamped per task at settle). The capability fact `ctx.bash.sandboxMode` reports the configured default so the tool layer advertises escalation only when this executor is mounted. The model learns of the sandbox only through result facts — the static bash tool description explains the denial marker; there is no current-mode statement in the system prompt.
 - **File effects only.** Network and process visibility are deliberately not restricted — the mode vocabulary does not pretend to cover what the backend does not enforce.
 - Process mechanics (spawn, process-group kills, output collection/spill, background handles, credential scrub) are inherited from [`dsh-bash-local`](../bash-local/); runner selection lives in [`dsh-sandbox-local`](../../sandbox/sandbox-local/).
 
@@ -38,21 +38,45 @@ The keyless consumer-integration proofs are `tests/bwrap.e2e.ts`, `tests/landloc
 
 ### Bash tool schema, indirectly
 
-**What the model sees**: The generated [`dsh-tool-bash` schemas](../../../docs/tool-catalog.md#deepseek-aidsh-tool-bash) are the baseline. By advertising a confining `sandboxMode`, this backend augments `bash` with `sandbox_permissions` using enum `workspace-write` | `danger-full-access` and with `justification`. The backend adds no prompt prose, and the session's effective mode remains unstated.
+#### What the model sees
 
-**Token effect**: Small fixed schema increment on requests where `bash` is visible; mode switches add no context tokens.
+The generated [`dsh-tool-bash` schemas](../../../docs/tool-catalog.md#deepseek-aidsh-tool-bash) are the baseline. By advertising a confining `sandboxMode`, this backend augments `bash` with `sandbox_permissions` using enum `workspace-write` | `danger-full-access` and with `justification`. The backend adds no prompt prose, and the session's effective mode remains unstated.
+
+#### Token effect
+
+Small fixed schema increment on requests where `bash` is visible; mode switches add no context tokens.
+
+#### KV Cache effect
+
+Prefix-stable while the executor advertises the same sandbox capabilities. Changing those capabilities alters the `bash` schema and may invalidate reuse from that definition; per-session mode switches do not.
 
 ### Bash tool result, indirectly
 
-**What the model sees**: After ordinary bounded output, a denied call appends exactly `[sandbox: file access denied under <mode> mode]`. When escalation is available it next appends `[sandbox: escalation available — retry this exact command once with sandbox_permissions (the narrowest wider mode that suffices) + justification; the approval prompt asks the user]`. A settled background runner failure instead appends `[sandbox: the sandbox runner itself failed under <mode> mode — the command did not run; this is a sandbox problem, not a command failure]`.
+#### What the model sees
 
-**Token effect**: Zero additional tokens on an unremarkable allowed run beyond ordinary output. Denial or failure adds the quoted conditional marker, retained until compaction.
+After ordinary bounded output, a denied call appends exactly `[sandbox: file access denied under <mode> mode]`. When escalation is available it next appends `[sandbox: escalation available — retry this exact command once with sandbox_permissions (the narrowest wider mode that suffices) + justification; the approval prompt asks the user]`. A settled background runner failure instead appends `[sandbox: the sandbox runner itself failed under <mode> mode — the command did not run; this is a sandbox problem, not a command failure]`.
+
+#### Token effect
+
+Zero additional tokens on an unremarkable allowed run beyond ordinary output. Denial or failure adds the quoted conditional marker, retained until compaction.
+
+#### KV Cache effect
+
+Append-only; newly visible content follows the reusable request prefix and does not invalidate existing KV-cache entries.
 
 ### Bash tool error, indirectly
 
-**What the model sees**: If no runner can enforce a confined mode, the foreground call propagates the [`SANDBOX_UNAVAILABLE` error owned by `dsh-sandbox`](../../sandbox/sandbox/README.md#confinement-error-indirectly). For an execution-time runner failure, this backend supplies the first stderr line as its detail.
+#### What the model sees
 
-**Token effect**: Conditional error text is visible for that call and retained in history until compaction.
+If no runner can enforce a confined mode, the foreground call propagates the [`SANDBOX_UNAVAILABLE` error owned by `dsh-sandbox`](../../sandbox/sandbox/README.md#confinement-error-indirectly). For an execution-time runner failure, this backend supplies the first stderr line as its detail.
+
+#### Token effect
+
+Conditional error text is visible for that call and retained in history until compaction.
+
+#### KV Cache effect
+
+Append-only; newly visible content follows the reusable request prefix and does not invalidate existing KV-cache entries.
 
 ## Known Limitations and Deferred Work