docs(divergences): broaden into an Ink relationship record; strengthen the alignment-is-a-means principle (#204)

ink-divergences.md used to record only divergences from Ink. Broaden it into the
single record point for the *whole* Ink relationship: it now also records deliberate
alignments (intentional sameness) as first-class entries, not just differences.

- Reframe the title + intro: three relationship kinds (deliberate alignments,
  intentional divergences, non-behavioral notes), each a conscious decision.
- Elevate + strengthen the governing principle: aligning to Ink is only a means to
  reduce bugs, never the goal — correctness and Vue philosophy outrank parity, and
  "because Ink does it" is never on its own a justification.
- Add a first-class "Deliberate Alignments" section; promote the two deliberate-
  sameness records (commit-timing Ink-alignment, literal-tab measure-vs-paint, the
  latter keeping its existing [VOUCHED @hyf0]) out of Non-Behavioral Notes into it.
- Restructure the classification flow to split deliberate match vs deliberate
  divergence first ("How to Classify an Entry").
- Update AGENTS.md guidance and the two stale cross-references to the renamed
  headings (accessibility-api.md + the in-file ARIA entry).

No existing divergence entry's substance changed; no [VOUCHED] stamp was added or
removed (AI cannot self-bless). Reviewed by Codex + an independent reviewer.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.agents/docs/accessibility-api.md

@@ -29,7 +29,8 @@ to receive them and no browser to read them.
   `aria-role` ports from Ink/HTML unchanged — it is the runtime-compatible escape, not the
   type-safe path.
 - This is a Vue-idiom + reasonableness choice, **not parity** (Ink is kebab). See the
-  "Why align to Ink — and when not to" principle in [ink-divergences](./ink-divergences.md).
+  "The governing principle: correctness first, alignment is only a means" section in
+  [ink-divergences](./ink-divergences.md).
 
 ## Type-safety boundary (run-verified: `tsc` + `vue-tsc`)