iter kernel-extension-mechanics.tidy: architect drift items — present-state + plugin-migration aftermath

Audit Step 3 fix path. Architect drift review at milestone close
surfaced 8 items (3 high, 4 medium, 1 low). Resolved 7 inline as
mechanical text rewrites + 2 source-rustdoc cleanups; the 1 low
(cycle-avoidance pattern documentation in design ledger) is
deferred — architect flagged it "Note, do not push" because the
pattern is implementation mechanism, not language semantics,
and is already documented in the load-bearing place
(`crates/ailang-kernel-stub/src/lib.rs //!`).

CLAUDE.md (2 sites):
  - Lead paragraph: "this file carries [...] in-tree skill system"
    → reframe to "this file carries [...] orchestrator discipline
    (the skill system itself lives in the ~/dev/skills/ plugin
    and is wired in via .claude/dev-cycle-profile.yml)".
  - Code-layout table: new row for `crates/ailang-kernel-stub/`
    documenting the zero-dep leaf design, the parse-hop location
    in `ailang-surface`, and the planned retirement at raw-buf
    landing.

design/INDEX.md (2 sites):
  - Project-ecosystem "Skills" bullet: in-tree `skills/` path +
    `skills/README.md` reference → `~/dev/skills/` plugin +
    in-tree per-project profile. Also added `docwriter` and
    `boss` to the enumerated skill list (8 in total) for
    completeness.
  - kernel-extensions row 111: added stub-retirement plan to the
    annotation so the spine names the future state, not just the
    in-tree reader of `lib.rs //!`.

design/models/0007-kernel-extensions.md (3 sites):
  - § "Migration policy" subsection: 4 bullets transitioned
    forward → present-state per honesty-rule. References to
    `loader.rs:98-108` / `workspace.rs:308-311, 467, 2655` as
    if hardcoded paths still existed → described as past state
    that has been replaced by the generic flag-filter. Codegen-
    intercept-migration bullet kept forward-looking because the
    `try_emit_primitive_instance_body` migration is *actually*
    still pending (deferred to Series milestone per spec
    § Out-of-scope).
  - § "Feature-acceptance argument": "the bounded push-only
    mutation surface — gated by the `Series` effect" — internal
    contradiction with three earlier statements that "Series
    carries no separate algebraic effect; mutation is mode-
    tracked, not effect-tracked". Re-framed to "gated by
    uniqueness mode-tracking on the owned `Series` value (not by
    an algebraic effect; see §"Coexistence" below)".
  - § "Coexistence" "Algebraic effects" bullet: "Reused
    unchanged. The `Series` effect is a new name" — same
    contradiction. Re-framed to "Not extended by Series.
    Mutation discipline lives in the uniqueness/mode system; the
    algebraic-effects set is unchanged".

Source rustdoc (2 sites):
  - `crates/ailang-core/tests/design_index_pin.rs:117` comment
    "skills/**/SKILL.md" → "any in-tree project-discipline
    document (e.g. CLAUDE.md)" — the allowlist comment now
    matches what the test actually does (no allowlist enforced
    in code; any existing path passes).
  - `crates/ailang-core/tests/design_schema_drift.rs:419`
    rustdoc: "RED until `skills/implement` mini-mode adds it"
    → "RED until the `implement` skill (mini-mode dispatch)
    adds it" — same skill, post-plugin-migration framing.

Architect items not addressed in this tidy:
  - 0007 § "The plugin contract (consolidated)" forward-intent
    reference to `try_emit_primitive_instance_body` migration —
    architect flagged as edge-case-acceptable per the explicit
    STATUS carve-out (the migration IS still pending). No
    change.
  - Cycle-avoidance pattern documentation (low): deferred per
    architect recommendation.

Tests green (664/0); workspace_pin module-count assertion picked
up from a844de3 carries through.

crates/ailang-core/tests/design_index_pin.rs

@@ -114,7 +114,7 @@ fn every_contract_names_a_resolvable_ratifying_test() {
     // clause 2 — ratifying-test token resolves to a real file under
     // crates/**/tests, crates/**/src (in-source #[cfg(test)] mod
     // tests are first-class ratifiers — spec OQ1/OQ2), bench/, or
-    // skills/**/SKILL.md.
+    // any in-tree project-discipline document (e.g. CLAUDE.md).
     let (contracts, _) = index_tables();
     for row in &contracts {
         // columns: id | consumer/lifetime | ratifying-test | link

crates/ailang-core/tests/design_schema_drift.rs

@@ -416,8 +416,8 @@ fn design_md_anchors_every_parammode_variant() {
 ///      block must report PRESENT under the scoped helper.
 ///
 /// Gitea issue #10. The helper `anchor_in_jsonc_block` does not yet exist —
-/// this test is RED until `skills/implement` mini-mode adds it and re-routes
-/// the six existing call sites onto it.
+/// this test is RED until the `implement` skill (mini-mode dispatch) adds it
+/// and re-routes the six existing call sites onto it.
 #[test]
 fn anchor_presence_check_is_scoped_to_jsonc_blocks() {
     // Anchor mentioned only in prose — the false-pass surface. The whole