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/tools/git/detect-platform.ps1

@@ -0,0 +1,83 @@
+# detect-platform.ps1 - Detect git platform (Gitea or GitHub) for current repo
+# Usage: . .\detect-platform.ps1; Get-GitPlatform
+#        or: .\detect-platform.ps1 (prints platform name)
+
+function Get-GitPlatform {
+    [CmdletBinding()]
+    param()
+
+    $remoteUrl = git remote get-url origin 2>$null
+
+    if ([string]::IsNullOrEmpty($remoteUrl)) {
+        Write-Error "Not a git repository or no origin remote"
+        return $null
+    }
+
+    # Check for GitHub
+    if ($remoteUrl -match "github\.com") {
+        return "github"
+    }
+
+    # Check for common Gitea indicators
+    # Gitea URLs typically don't contain github.com, gitlab.com, bitbucket.org
+    if ($remoteUrl -notmatch "gitlab\.com" -and $remoteUrl -notmatch "bitbucket\.org") {
+        # Assume Gitea for self-hosted repos
+        return "gitea"
+    }
+
+    return "unknown"
+}
+
+function Get-GitRepoInfo {
+    [CmdletBinding()]
+    param()
+
+    $remoteUrl = git remote get-url origin 2>$null
+
+    if ([string]::IsNullOrEmpty($remoteUrl)) {
+        Write-Error "Not a git repository or no origin remote"
+        return $null
+    }
+
+    # Extract owner/repo from URL
+    # Handles: git@host:owner/repo.git, https://host/owner/repo.git, https://host/owner/repo
+    $repoPath = $remoteUrl
+    if ($remoteUrl -match "^git@") {
+        $repoPath = ($remoteUrl -split ":")[1]
+    } else {
+        # Remove protocol and host
+        $repoPath = $remoteUrl -replace "^https?://[^/]+/", ""
+    }
+
+    # Remove .git suffix if present
+    $repoPath = $repoPath -replace "\.git$", ""
+
+    return $repoPath
+}
+
+function Get-GitRepoOwner {
+    [CmdletBinding()]
+    param()
+
+    $repoInfo = Get-GitRepoInfo
+    if ($repoInfo) {
+        return ($repoInfo -split "/")[0]
+    }
+    return $null
+}
+
+function Get-GitRepoName {
+    [CmdletBinding()]
+    param()
+
+    $repoInfo = Get-GitRepoInfo
+    if ($repoInfo) {
+        return ($repoInfo -split "/")[-1]
+    }
+    return $null
+}
+
+# If script is run directly (not dot-sourced), output the platform
+if ($MyInvocation.InvocationName -ne ".") {
+    Get-GitPlatform
+}