Merge upstream main and migrate daily focus board plugin

Adopt the Agent Plugins v1.0.0 namespaced composition model from #2546. Bundle the reusable daily-focus-board canvas into Ember only and remove its obsolete standalone catalog manifest.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 52be9c67-3ae4-4610-93d0-fe0b7ab95ccb

extensions/daily-focus-board/.github/plugin/plugin.json

@@ -1,19 +0,0 @@
-{
-  "name": "daily-focus-board",
-  "description": "A warm, executive-function-friendly daily focus board rendered in a GHCP canvas and backed by a JSON file your AI partner can read and write. Tasks (to-do -> in progress -> done) with progress notes, numeric counters, Focus mode, kind carryover, a brain-dump box, reduced motion, and a live clock. Universal companion to the daily-focus-board skill for people who run the GitHub Copilot app.",
-  "version": "0.1.0",
-  "author": {
-    "name": "jennyf19",
-    "url": "https://github.com/jennyf19"
-  },
-  "keywords": [
-    "focus",
-    "daily-planner",
-    "executive-function",
-    "adhd-friendly",
-    "productivity",
-    "canvas"
-  ],
-  "logo": "assets/preview.png",
-  "extensions": "."
-}