feat(arcrun): mira wiki page with tag filter + accumulated WIP

- landing/app/mira/wiki: tag=mira-wiki list now shows all wiki paragraphs
  (depends on KBDB tag filter exposed in matrix/kbdb commit, separate repo)
- landing: app/mira hub + feed split + various WIP from prior sessions
- registry/components: claude_api / kbdb_create_block / kbdb_get / km_writer /
  platform_crypto / auth_oauth2 contracts + main.go (accumulated)
- .component-builds: pkg-lock updates + index.ts adjustments (WIP)
- .agents/specs/arcrun/frontend-redesign: design notes
- docs/test_credentials, docs/user_requirements/arcrun-landing-page: WIP docs
- cypher-executor: auth-dispatcher / wasi-shim adjustments (WIP)

Includes accumulated work from prior sessions plus the wiki UI tag-filter
update that surfaces the AI-generated wiki paragraphs at /mira/wiki.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

registry/components/km_writer/component.contract.yaml

@@ -0,0 +1,67 @@
+canonical_id: "km_writer"
+display_name: "KM Writer"
+category: "api"
+version: "v1"
+wasi_target: "preview1"
+stability: "floating"
+runtime_compat:
+  - "cf-workers"
+  - "workerd"
+constraints:
+  max_size_kb: 2048
+  max_cold_start_ms: 50
+  no_network_syscall: false
+  no_filesystem_syscall: true
+  io_model: "stdin_stdout_json"
+input_schema:
+  type: object
+  required: [action, mira_url, token]
+  properties:
+    action:
+      type: string
+      description: "操作類型：read_journal | read_journal_date | append_journal | list_pages | read_page | write_page"
+      enum: [read_journal, read_journal_date, append_journal, list_pages, read_page, write_page]
+    mira_url:
+      type: string
+      description: "Mira 服務基礎 URL（例：https://mira.uncle6.me）"
+    token:
+      type: string
+      description: "Mira MIRA_TOKEN（Bearer token）"
+    content:
+      type: string
+      description: "內容（append_journal / write_page 時必填）"
+    timestamp:
+      type: string
+      description: "ISO 8601 時間戳（append_journal 時選填，影響日期和時間顯示）"
+    date:
+      type: string
+      description: "日期 YYYY-MM-DD（read_journal_date 時必填）"
+    name:
+      type: string
+      description: "頁面名稱（read_page / write_page 時必填）"
+output_schema:
+  type: object
+  properties:
+    success:
+      type: boolean
+    data:
+      type: object
+      description: "Mira API 回應資料"
+    error:
+      type: string
+      description: "錯誤訊息（success=false 時）"
+gherkin_tests:
+  - scenario: "缺少 action"
+    given: '{"mira_url":"https://mira.uncle6.me","token":"abc"}'
+    then_contains: '{"success":false'
+  - scenario: "缺少 token"
+    given: '{"action":"list_pages","mira_url":"https://mira.uncle6.me"}'
+    then_contains: '{"success":false'
+tags: [km, journal, logseq, mira, knowledge-management]
+description: "讀寫 Mira leo-graph 的 journals 和 pages。透過 host function 呼叫 Mira /km/* API，支援讀取、新增日誌條目，以及讀寫頁面。"
+config_example: |
+  append_to_journal:
+    action: "append_journal"
+    mira_url: "https://mira.uncle6.me"
+    token: "<mira_token>"
+    content: "今天完成了 arcrun km_writer 元件"