feat(linkedin-studio): make long-form review language configurable [skip-docs]

Wave 3 / Step 9 of the remediation plan (Phase 1 — usable by a non-author).

The long-form review layer shipped Norwegian-locked: language-reviewer graded
unconditional Norwegian, voice-scrubber's gold standard was 'approved Norwegian
editions', and the editorial/content craft gates pointed at a 'skrivekontrakt §C2'
that does not ship. A non-Norwegian adopter would get English prose graded against
Norwegian idiom and a gate that depends on an unshipped contract.

- config/edition-state.template.json: add additive 'language' field (top-level,
  default 'en') + a _doc entry. Threads into the language-dependent agents.
- agents/language-reviewer.md: new 'Language parameter' section — Norwegian-specific
  checks (anglicism->Norwegian idiom, kanselli-stil) apply only when language=='no';
  any other value grades that language's equivalents and never flags idiomatic
  English as an anglicism. Default 'en'.
- agents/voice-scrubber.md: gold standard reframed to 'approved editions in the
  configured language'; the Norwegian-chronicle calibration is the language=='no'
  instantiation.
- agents/editorial-reviewer.md + agents/content-reviewer.md: the in-tree checklist
  is now the operative, self-contained source of truth; Maskinrommet §C2 is an
  optional upstream contract that does NOT ship (available only on the author's
  runs). The gates work for an adopter without it.
- commands/newsletter.md: thread 'language' through the Step 6.5 cold-inputs and the
  per-reviewer call inputs; the writing contract is now 'if it ships'.

Norwegian remains fully working when language: no (the author's case).

fact-reviewer.md was in the plan's file list but needed no change on inspection:
its F1-F4 checks (claims/quotes/numbers/sources) are language-agnostic; its
'Norwegian' mentions are boundary notes vs language-reviewer, which stay correct.

[skip-docs]: three-doc + version reconciliation is Step 21 (pre-review-gate); these
intermediate Wave commits are not pushed before the /trekreview gate.

Verify: edition-state JSON parses + has top-level language 'en'; language-reviewer
has 'language ==' references and no unconditional-Norwegian assertion; editorial
§C2 reframed to in-tree fallback ('operative source', 'does not ship'); agent
fixtures 35/35 pass; structural lint exit 0 (61 passed).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plugins/linkedin-studio/commands/newsletter.md

@@ -1041,21 +1041,26 @@ command runs — see `commands/headless-review.md` for the full cold contract):
    ```
    Record the frozen path; pass *that* path (not the live draft) to every reviewer.
 
-2. **Resolve the cold inputs.** The writing contract (`<serie>/../../docs/skrivekontrakt.md`
-   → plugin mirror → `references/longform-quality-rules.md`) and the active
+2. **Resolve the cold inputs.** The **review language** (`edition-state.language`,
+   default `en` — tells `language-reviewer` and `voice-scrubber` which language's
+   rules to grade against; Norwegian-specific checks fire only when `language: no`),
+   the writing contract *if it ships* (`<serie>/../../docs/skrivekontrakt.md` →
+   plugin mirror → `references/longform-quality-rules.md`; absent for an adopter,
+   the craft agents' in-tree checklists are self-contained), and the active
    personas (`articles.NN.personas`, primær identified). Nothing else.
 
 3. **Fan out the five archetypes in parallel** — issue them in a SINGLE message
    (multiple `Task` tool-uses) from THIS command layer in the foreground
    (principle 4), `subagent_type` namespaced:
    - `linkedin-studio:content-reviewer` — argument integrity (C1–C5)
-   - `linkedin-studio:language-reviewer` — Norwegian language (L1–L5)
+   - `linkedin-studio:language-reviewer` — language quality (L1–L5; grades against `edition-state.language`, Norwegian-specific rules when `language: no`)
    - `linkedin-studio:fact-reviewer` — cold re-verification (F1–F4, 🔴/🟡/🟢, incl. pivot premises)
    - `linkedin-studio:persona-reviewer` `mode: resonans` — **one call per active persona**
    - `linkedin-studio:persona-reviewer` `mode: konverter` — **primær only** (hook)
 
    Each call's prompt carries ONLY the cold-contract inputs (frozen draft path,
-   contract path, persona for the persona modes) + the instruction to ignore any
+   `language`, contract path if it ships, persona for the persona modes) + the
+   instruction to ignore any
    framing about prior versions / cuts / pivots. **Never** paste history or
    summarize "what we changed" into a reviewer prompt — that is the context
    pollution the package exists to eliminate.