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/milestone-create.ps1

@@ -0,0 +1,98 @@
+# milestone-create.ps1 - Create milestones on Gitea or GitHub
+# Usage: .\milestone-create.ps1 -Title "Title" [-Description "Description"] [-Due "YYYY-MM-DD"]
+
+[CmdletBinding()]
+param(
+    [Alias("t")]
+    [string]$Title,
+
+    [Alias("d")]
+    [string]$Description,
+
+    [string]$Due,
+
+    [switch]$List,
+
+    [Alias("h")]
+    [switch]$Help
+)
+
+$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
+. "$ScriptDir\detect-platform.ps1"
+
+function Show-Usage {
+    @"
+Usage: milestone-create.ps1 [OPTIONS]
+
+Create or list milestones on the current repository (Gitea or GitHub).
+
+Versioning Convention:
+    - Features get dedicated milestones
+    - Pre-MVP milestones MUST use 0.0.x and MUST start at 0.0.1
+    - 0.1.0 is reserved for MVP release
+    - After MVP, continue semantic progression (0.1.x, 0.2.x, ...)
+
+Options:
+    -Title, -t TITLE        Milestone title/version (e.g., "0.0.1")
+    -Description, -d DESC   Milestone description
+    -Due DATE               Due date (YYYY-MM-DD format)
+    -List                   List existing milestones
+    -Help, -h               Show this help message
+
+Examples:
+    .\milestone-create.ps1 -List
+    .\milestone-create.ps1 -t "0.0.1" -d "Pre-MVP Foundation Sprint"
+    .\milestone-create.ps1 -t "0.1.0" -d "MVP Release" -Due "2025-03-01"
+"@
+    exit 1
+}
+
+if ($Help) {
+    Show-Usage
+}
+
+$platform = Get-GitPlatform
+
+if ($List) {
+    switch ($platform) {
+        "github" {
+            gh api repos/:owner/:repo/milestones --jq '.[] | "\(.number)`t\(.title)`t\(.state)`t\(.open_issues)/\(.closed_issues) issues"'
+        }
+        "gitea" {
+            tea milestones list
+        }
+        default {
+            Write-Error "Could not detect git platform"
+            exit 1
+        }
+    }
+    exit 0
+}
+
+if (-not $Title) {
+    Write-Error "Title is required (-t) for creating milestones"
+    Show-Usage
+}
+
+switch ($platform) {
+    "github" {
+        $payload = @{ title = $Title }
+        if ($Description) { $payload.description = $Description }
+        if ($Due) { $payload.due_on = "${Due}T00:00:00Z" }
+
+        $json = $payload | ConvertTo-Json -Compress
+        $json | gh api repos/:owner/:repo/milestones --method POST --input -
+        Write-Host "Milestone '$Title' created successfully"
+    }
+    "gitea" {
+        $cmd = @("tea", "milestones", "create", "--title", $Title)
+        if ($Description) { $cmd += @("--description", $Description) }
+        if ($Due) { $cmd += @("--deadline", $Due) }
+        & $cmd[0] $cmd[1..($cmd.Length-1)]
+        Write-Host "Milestone '$Title' created successfully"
+    }
+    default {
+        Write-Error "Could not detect git platform"
+        exit 1
+    }
+}