docs: fix chat status names and auto-archive behavior claims - #28570

…le (#28594)

Agent-authored docs PRs kept leaking implementation detail into
user-facing pages: chat status enum values and `root_chat_id` on the
auto-archive page (#28570, flagged by reviewers), and RBAC resource
names and response fields in the first revision of #28482. The
correction pattern was the same each time: state the behavior in the
reader's terms.

This encodes that pattern as one canonical rule with citations in every
file that carries the exact-values instruction:

- `docs/.style/content-guidelines.md`: new guiding principle "Evidence
justifies a claim; it does not belong in the claim". The test is scoped
to the task the page documents, with a first-match ladder: exact value
where the reader types or receives it, visible product wording where the
screen shows it, plain reader's-terms prose otherwise. An identifier set
described as a set resolves at the lowest rung any member reaches.
Stripped identifiers are named (file and symbol) in the PR discussion as
a best-effort pointer for the reviewer. Cross-linked with
verify-exact-values, describe-current-version, the routing table, and
word-choice. Also repairs a pre-existing broken feature-stages link.
- `docs/.style/style-guide/word-choice.md`: the internal-references
section notes that implementation identifiers follow the (conditional)
canonical rule, covering the prose-edit route that AGENTS.md sends to
the prose style guide.
- `.claude/docs/DOCS_STYLE_GUIDE.md`: the Accuracy Standards section
head and Key Principles item 2 carry the same qualifier, since this
always-loaded file is where agents get the unqualified exact-values
instruction.
- `.claude/skills/write-docs/SKILL.md`: workflow step 1 marks copied
identifiers as verification inputs with a forward link; citation-only
"Evidence versus claim" section; matching anti-pattern bullet and a
checklist item that defers the stripped-identifier disclosure to the
canonical rule.
- `.claude/skills/doc-check/SKILL.md`: "Evidence versus claim" check
scoped to identifiers the change adds or touches, working from the diff
(doc-check does not police the disclosure, which it cannot see);
pre-existing violations on untouched pages are informational only.

The motivating page (`chat-auto-archive.md`) was fixed separately in
#28570 (DOCS-722, merged). Corpus sweep for other violations: DOCS-730.
Lint and link coverage for the `.claude` and `docs/.style` trees:
DOCS-729.

Linear: DOCS-728 https://linear.app/codercom/issue/DOCS-728

<details>
<summary>CI note (docs-only PR)</summary>

This PR changes only Markdown under `docs/.style/` and `.claude/` (no
`site/src` or other product code).

- The `ci` workflow's docs-relevant jobs pass on the head commit:
`changes`, `gen`, `lint`, `lint-docs`, `fmt`, `offlinedocs`, `required`.
Heavy build/test jobs are correctly skipped for a docs-only change.
(Run: https://github.com/coder/coder/actions/runs/32986743037)
- `Pixel / Review` (frontend visual snapshots) is unrelated to the
changed paths and is treated as an unrelated flake.

</details>

> This PR was created with AI assistance (Coder Agents).