feat: integrate framework files into monorepo under packages/mosaic/framework/

Moves all Mosaic framework runtime files from the separate bootstrap repo
into the monorepo as canonical source. The @mosaic/mosaic npm package now
ships the complete framework — bin scripts, runtime configs, tools, and
templates — enabling standalone installation via npm install.

Structure:
  packages/mosaic/framework/
  ├── bin/          28 CLI scripts (mosaic, mosaic-doctor, mosaic-sync-skills, etc.)
  ├── runtime/      Runtime adapters (claude, codex, opencode, pi, mcp)
  ├── tools/        Shell tooling (git, prdy, orchestrator, quality, etc.)
  ├── templates/    Agent and repo templates
  ├── defaults/     Default identity files (AGENTS.md, STANDARDS.md, SOUL.md, etc.)
  ├── install.sh    Legacy bash installer
  └── remote-install.sh  One-liner remote installer

Key files with Pi support and recent fixes:
- bin/mosaic: launch_pi() with skills-local loop
- bin/mosaic-doctor: --fix auto-wiring for all 4 harnesses
- bin/mosaic-sync-skills: Pi as 4th link target, symlink-aware find
- bin/mosaic-link-runtime-assets: Pi settings.json patching
- bin/mosaic-migrate-local-skills: Pi skill roots, symlink find
- runtime/pi/RUNTIME.md + mosaic-extension.ts

Package ships 251 framework files in the npm tarball (278KB compressed).

packages/mosaic/framework/templates/agent/fragments/campsite-rule.md

@@ -0,0 +1,21 @@
+## Campsite Rule (MANDATORY)
+
+If you modify a line containing a policy violation, you MUST either:
+
+1. **Fix the violation properly** in the same change, OR
+2. **Flag it as a deferred item** with documented rationale
+
+**"It was already there" is NEVER an acceptable justification** for perpetuating a violation in code you touched. Touching it makes it yours.
+
+Examples of violations you must fix when you touch the line:
+
+- `as unknown as Type` double assertions — use type guards instead
+- `any` types — narrow to `unknown` with validation or define a proper interface
+- Missing error handling — add it if you're modifying the surrounding code
+- Suppressed linting rules (`// eslint-disable`) — fix the underlying issue
+
+If the proper fix is too large for the current scope, you MUST:
+
+- Create a TODO comment with issue reference: `// TODO(#123): Replace double assertion with type guard`
+- Document the deferral in your PR/commit description
+- Never silently carry the violation forward