docs: protocol audit 2026-05-25, update architecture + Obsidian vault

Audit:
- docs/AUDIT-2026-05-25.md: full protocol audit covering 8 findings
  (4 critical, 2 high, 5 medium, 4 low) with code references and fix
  effort estimates
- vault/Audit/Tasks.md: Obsidian Tasks plugin file tracking all audit
  items with priorities, due dates, and per-step checklists

Architecture docs updated for Wire format v2 and Wave 5/6 features:
- ARCHITECTURE.md: adds wzp-video to dependency graph and project
  structure; wire format updated to v2 (16B header, 5B MiniHeader);
  relay concurrency section corrected (DashMap+RwLock is current, not
  a future optimization); test count 571→702; Android note
- PROGRESS.md: Wave 5 and Wave 6 sections appended; test count 372→702;
  current status and open blockers as of 2026-05-25
- ROAD-TO-VIDEO.md: implementation status table inserted (✅/🟡/🔴/🔲
  per phase); 6-step critical path to first video call
- WZP-SPEC.md: MediaHeader updated to v2 (16B byte-aligned); MiniHeader
  updated to 5B with seq_delta; codec IDs 9-12 added (H.264/H.265/AV1);
  version negotiation section added

Obsidian vault (vault/):
- 114 files across Architecture/, PRDs/, Reports/, Android/,
  Reference/, Audit/ with YAML frontmatter
- 00 - Home.md index note with wiki links
- .obsidian/app.json config

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

vault/Reports/T1.2.1-report.md

@@ -0,0 +1,79 @@
+---
+tags: [report, wzp]
+type: report
+status: Approved
+---
+
+# T1.2.1 — Add rustdoc on `MediaType` variants and methods
+
+**Status:** Approved
+**Agent:** Kimi Code CLI
+**Started:** 2026-05-11T07:23Z
+**Completed:** 2026-05-11T07:24Z
+**Commit:** see git log
+**PRD:** ../PRD-wire-format-v2.md
+
+## What I changed
+
+- `crates/wzp-proto/src/media_type.rs:7-10` — added `///` doc comments to all 4 variants (`Audio`, `Video`, `Data`, `Control`)
+- `crates/wzp-proto/src/media_type.rs:14` — added `///` doc on `to_wire`
+- `crates/wzp-proto/src/media_type.rs:18` — added `///` doc on `from_wire`
+
+## Why these choices
+
+Follow-up from T1.2 review: coding standard #9 requires `///` on all public items. Added concise one-line docs matching the examples from the task spec.
+
+## Deviations from the task spec
+
+None.
+
+## Verification output
+
+```bash
+$ cargo doc -p wzp-proto --no-deps 2>&1 | grep -i "missing" || echo "no missing-doc warnings"
+no missing-doc warnings
+```
+
+```bash
+$ cargo clippy -p wzp-proto --all-targets -- -D warnings -W missing_docs 2>&1 | grep "media_type.rs:" | head -10
+# (no output — no missing-docs in media_type.rs)
+```
+
+```bash
+$ cargo build -p wzp-proto
+    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.49s
+```
+
+```bash
+$ cargo test -p wzp-proto --no-fail-fast
+running 112 tests
+test result: ok. 112 passed; 0 failed; ...
+```
+
+```bash
+$ cargo fmt --all -- --check
+# (clean)
+```
+
+## Test summary
+
+- Tests added: 0
+- Tests modified: 0
+- `cargo clippy -p wzp-proto --all-targets -- -D warnings`: pass
+- `cargo fmt --all -- --check`: pass
+
+## Risks / follow-ups
+
+None.
+
+## Reviewer checklist (filled in by reviewer)
+
+- [x] Code matches PRD intent
+- [x] Verification output is real (re-run if suspicious) — re-ran `clippy -W missing_docs | grep media_type.rs:` → zero hits.
+- [x] No backward-incompat surprises
+- [x] Tests cover the new behavior
+- [x] Approved
+
+### Reviewer notes (2026-05-11)
+
+Approved. All 4 variants and both methods carry concise, accurate `///` docs. Both Verify commands run this time. Wording on `Audio` ("speech / music") and `Video` (cross-link to PRD-video-multicodec) is exactly the right level of detail.