Phase 10: publish the documentation set + tick AGENTS.md 9 of 10

Phase 10 (the last phase of this project) is the project-docs pass. Update the
Gitea README, add the Mermaid source and rendered PNG, build the interactive
Archify map, add the Vikunja board tasks, and write the Outline AI-context
collection in Simplified Technical English.

Deliverables:
- README.md: status header, Phase 4 gap statement, "Architecture" section with
  embedded Mermaid + image + Archify link, "Documentation set" table, an
  explicit two-plane MQTT section (1883 plain+anonymous, 8883 TLS+ACLs), and
  the Android client's Usage Access and VpnService paths.
- AGENTS.md section 11: tick Phase 10, leave Phase 4 unticked, status line now
  "9 of 10 done - only Phase 4 outstanding".
- docs/architecture.mmd + docs/diagrams/architecture.png (mmdc).
- docs/archify/architecture.architecture.json + docs/architecture-map.html
  (Archify, showcase, 9/9 checks, 0 errors).
- docs/outline/00-index.md .. 04-agent-runbook.md (STE).
- docs/vikunja-tasks.json (Vikunja project "Internet Use Control", id 20).
- Obsidian note written to 010 inbox on .27; the obsidian-sorter proposed a
  folder and waits for the vault owner's approval.

Phase 4 (Python Windows computer client) is deliberately deferred and is NOT
built. Every document says so.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

docs/architecture.mmd

@@ -0,0 +1,29 @@
+flowchart LR
+    SAM["Sam<br/>browser dashboard"]
+    ADMIN["Admin app<br/>kotlin_phone_app_admin"]
+    HUB["Hub :8788<br/>read-only /ask"]
+    CADDY["Caddy on .35<br/>webrestrict.lab.audasmedia.com.au"]
+    CS["Control Service<br/>Go + SQLite :8791"]
+    APPRISE["Apprise :8210<br/>alerts + tamper reports"]
+
+    subgraph MQ["Mosquitto on .13 - two planes"]
+        TLS["8883 TLS<br/>per-device creds + topic ACLs"]
+        PLAIN["1883 plain + anonymous"]
+    end
+
+    PHONE["Kids' Android client<br/>Kotlin, Accessibility + overlay"]
+    OTHER["Other house consumers"]
+
+    SAM -->|HTTPS| CADDY
+    CADDY --> CS
+    ADMIN -->|"Bearer token /api/v1"| CS
+    HUB -->|"Bearer token /ask"| CS
+    CS -->|"retained config"| TLS
+    TLS -->|"own config topic"| PHONE
+    PHONE -->|"status + telemetry"| TLS
+    TLS -->|reports| CS
+    CS --> APPRISE
+    PLAIN -.->|legacy| OTHER
+
+    click CS "https://maps.lab.audasmedia.com.au/internet_use_control/docs/" "View Archify map"
+    click TLS "https://maps.lab.audasmedia.com.au/internet_use_control/docs/" "View Archify map"