feat: Extract PolyPilot.Core library for headless operation

[PureWeen]

Summary

Extracts all non-GUI logic from the MAUI app into a PolyPilot.Core (net10.0) class library so the orchestration engine, sessions, networking, persistence, and multi-agent system can run independently of any UI framework.

What moved

Category	Count	Destination
Models	29 files	PolyPilot.Core/Models/
Services	45 files	PolyPilot.Core/Services/
Interfaces	5 files	PolyPilot.Core/Services/

Stayed in MAUI: QrScannerService, KeyCommandService, TutorialService (platform-coupled).

Architecture

PolyPilot.Core (net10.0)          ← All logic: CopilotService, WsBridge, DevTunnel, orchestration
  ├── PolyPilot.Provider.Abstractions  ← Plugin contracts
  └── GitHub.Copilot.SDK               ← SDK dependency

PolyPilot (MAUI multi-TFM)       ← Thin UI shell, Blazor components
  └── ProjectReference → Core

PolyPilot.Gtk (net10.0+MAUI)     ← GTK frontend
  └── ProjectReference → Core

PolyPilot.Console (net10.0)      ← CLI frontend
  └── ProjectReference → Core

PolyPilot.Tests (net10.0)        ← ProjectReference → Core (replaces 73 Compile Include links)

Key design decisions

• Namespaces unchanged — PolyPilot.Models / PolyPilot.Services stay the same, minimizing churn
• InternalsVisibleTo on Core for MAUI, GTK, and Tests — no visibility changes needed
• MAUI-specific code compiles out — existing #if MACCATALYST/IOS/ANDROID blocks handle platform differences naturally in the net10.0 library
• No platform abstractions needed — the conditional compilation was already clean enough
• Git history preserved — all files detected as renames (100% similarity)

Test results

• ✅ dotnet build PolyPilot.slnx — full solution builds
• ✅ dotnet build PolyPilot.Core — net10.0 library builds clean
• ✅ dotnet build PolyPilot -f net10.0-maccatalyst — MAUI app builds
• ✅ dotnet test — 3154/3155 pass (1 flaky timing test unrelated to changes)
• ✅ Tests now use ProjectReference instead of 73 Compile Include links

[PureWeen]

🔍 Multi-Model Code Review — PR #513 (Re-review v3, after all fixes)

Summary

Extracts 74 files (29 Models + 45 Services) from the MAUI app into PolyPilot.Core — a multi-targeted library (net10.0, net10.0-android, net10.0-ios, net10.0-maccatalyst, net10.0-windows) so the engine can run headless while preserving platform-specific #if blocks.

CI Status

⚠️ No CI checks reported on this branch.

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All Previous Findings — Final Status

#	Round	Severity	Finding	Status
1	R1	🔴	Console missing bundled CLI binary	✅ FIXED
2	R1	🟢	Provider.Abstractions SDK version skew	✅ FIXED
3	R2	🔴	Dead #if platform blocks in net10.0 Core	✅ FIXED — Core multi-targets + runtime checks
4	R3	🔴	IsIOS() returns true on Mac Catalyst → desktop misidentified as mobile	✅ FIXED — IsMacCatalyst() exclusion added
5	R3	🟡	Missing FrameworkReference for Windows (System.Windows.Automation)	✅ FIXED — conditional Microsoft.WindowsDesktop.App ref added

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What Looks Good ✅

• Clean extraction — all 74 files are 100% similarity renames, zero source modifications to moved files
• Multi-targeting — Core compiles with platform symbols on each TFM, preserving all #if blocks
• Runtime checks — PlatformHelper, LinkHelper, CopilotService, UsageStatsService correctly use OperatingSystem.Is*() with Mac Catalyst exclusion
• InternalsVisibleTo correctly covers MAUI, GTK, and Tests
• Test simplification — 73 Compile Include links replaced with single ProjectReference
• All structural test paths properly updated across 11 test files
• Git history preserved — all renames detected at 100% similarity
• SDK versions aligned — 0.2.1 across all 4 projects
• Windows build — conditional FrameworkReference for UI Automation

Test Coverage

✅ 3134/3134 tests pass — zero failures.

Recommended Action

✅ Approve — all findings from 3 rounds of review have been addressed. Solution builds clean, full test suite passes.