Release v0.2.0: Task comments, recurring calendar, system tray, app branding

New features:
- Task comments with date-stamped entries and last-comment summary
- Recurring tasks expanded on calendar (daily/weekly/monthly/yearly)
- System tray mode replacing CMD window (Windows/macOS/Linux)
- Ironpad logo as exe icon, tray icon, favicon, and header logo

Technical changes:
- Backend restructured for dual-mode: dev (API-only) / prod (tray + server)
- tray-item crate for cross-platform tray, winresource for icon embedding
- Calendar view refactored with CalendarEntry interface for recurring merging
- Added CHANGELOG.md, build-local.ps1, version bumped to 0.2.0

Co-authored-by: Cursor <cursoragent@cursor.com>

build-local.ps1

@@ -0,0 +1,40 @@
+# build-local.ps1 — Build a local release package for testing
+# Creates: release/ironpad.exe + release/static/
+# Usage: .\build-local.ps1
+
+$ErrorActionPreference = "Stop"
+$root = $PSScriptRoot
+
+Write-Host "`n=== Ironpad Local Build ===" -ForegroundColor Cyan
+
+# 1. Build frontend
+Write-Host "`n[1/4] Building frontend..." -ForegroundColor Yellow
+Push-Location "$root\frontend"
+npm run build
+if ($LASTEXITCODE -ne 0) { Pop-Location; throw "Frontend build failed" }
+Pop-Location
+
+# 2. Build backend (release)
+Write-Host "`n[2/4] Building backend (release)..." -ForegroundColor Yellow
+Push-Location "$root\backend"
+cargo build --release
+if ($LASTEXITCODE -ne 0) { Pop-Location; throw "Backend build failed" }
+Pop-Location
+
+# 3. Assemble release folder
+Write-Host "`n[3/4] Assembling release folder..." -ForegroundColor Yellow
+$releaseDir = "$root\release"
+if (Test-Path $releaseDir) { Remove-Item -Recurse -Force $releaseDir }
+New-Item -ItemType Directory -Path $releaseDir | Out-Null
+New-Item -ItemType Directory -Path "$releaseDir\static" | Out-Null
+
+Copy-Item "$root\backend\target\release\ironpad.exe" "$releaseDir\ironpad.exe"
+Copy-Item "$root\frontend\dist\*" "$releaseDir\static\" -Recurse
+
+# 4. Done
+$size = [math]::Round((Get-Item "$releaseDir\ironpad.exe").Length / 1MB, 1)
+Write-Host "`n[4/4] Done!" -ForegroundColor Green
+Write-Host "  Binary:  $releaseDir\ironpad.exe ($size MB)"
+Write-Host "  Static:  $releaseDir\static\"
+Write-Host "`nTo run:  cd release && .\ironpad.exe" -ForegroundColor Cyan
+Write-Host "(Tray icon will appear - right-click for menu)`n"