docs(governance): owner confirmation on remaining 17 decisions (register v0.9.5)

Closes the 'Proposed / Owner Confirmation Required' state for every
decision in the register except DEC-020 (license, explicitly deferred
and now the only public-release-gating decision outstanding).

Accepted as recommended:
  DEC-001 (Alpha → Beta → Public release sequence),
  DEC-002 (all five platforms as MVP target, staged release allowed),
  DEC-003 (iOS minimum: iOS 13),
  DEC-005 (Android target SDK: Play-required API on upload date),
  DEC-006 (single active server connection in MVP),
  DEC-007/008/009/010 (AEC + AGC + NS + HPF defaults),
  DEC-011 (platform-native audio first),
  DEC-012 (legal/trademark/licensing review as a release gate),
  DEC-013 (SQLite or equivalent for non-secret state),
  DEC-016 (no automatic diagnostics upload),
  DEC-017 (crash reporting disabled for MVP),
  DEC-018 (product name: Chanora),
  DEC-019 (drafted non-affiliation wording),
  DEC-021 (Apple App Store SDK gate: Xcode 26+ / iOS 26 SDK+ on/after 2026-04-28).

Modified from the original recommendation by explicit owner ruling:
  - DEC-004: Android minimum raised to API 28 (Android 9.0) from the
    recommended API 24. Rationale: simpler audio path (AAudio stable
    from API 28), narrower compatibility / privacy / scoped-storage
    surface. Affects the Android spike's minSdk=24 in product code:
    apps/chanora_flutter will need minSdk=28.
  - DEC-015: MVP product language expanded to English + Chinese
    (Simplified) from the recommended English-only. Rationale: the
    demonstrated TS3-compatible-server audience (verified live against
    cn.teamspeak.app) and broader TS3 audience include substantial
    Chinese-speaking users. Adds zh-Hans translation, font, and
    text-length-budget work to MVP. Server-provided content is still
    preserved verbatim per ADR-008.

Still Open / Deferred:
  - DEC-020 license model. The only remaining release-gating decision.

Documentation updates:
  - product-decision-register.md → v0.9.5. §3 statuses updated, §4
    renamed Recommended → Accepted with MODIFIED rows annotated,
    §6 collapsed to DEC-020 only, §7 dated and statused for every
    decision, change-history entry added.
  - poc-results-summary.md → v0.3.0. §4 expanded with the
    2026-05-14 owner-confirmation pass table. RISK-PoC-004 closed.
    New RISK-PoC-006 (Android minSdk move 24 → 28) and RISK-PoC-007
    (MVP language expansion to en + zh-Hans) added.
  - CHANGELOG entry under [Unreleased].

CHANGELOG.md

@@ -48,6 +48,22 @@ This project is expected to follow a Conventional Commits style workflow.
 
 ### Changed
 
+- `docs/governance/product-decision-register.md` bumped to v0.9.5:
+  owner confirmation on all 17 previously-Proposed decisions
+  (DEC-001..010, 012, 015..019, 021). Sixteen were Accepted as
+  recommended; two were modified by the owner — **DEC-004**
+  Android minimum raised from API 24 to **API 28**, and
+  **DEC-015** product language for MVP expanded from English-only
+  to **English + Chinese (Simplified)**. DEC-020 license remains
+  Open / Deferred and is now the only public-release-gating
+  decision outstanding. §4 renamed "Recommended" → "Accepted MVP
+  Defaults" with MODIFIED rows annotated. §6 collapsed to the
+  single remaining DEC-020 item. §7 dated and statused for every
+  decision.
+- `docs/governance/poc-results-summary.md` bumped to v0.3.0:
+  RISK-PoC-004 closed by the owner-confirmation pass; new
+  RISK-PoC-006 (Android `minSdk` move 24 → 28 for product code)
+  and RISK-PoC-007 (MVP language expansion to en + zh-Hans) added.
 - `docs/architecture/proof-of-concept-plan.md` bumped to v0.3.0 to
   promote the audio PoC from PARTIAL PASS to PASS after the Android
   mobile half was closed; all six PoC plan entries are now PASS.