feat(rust): add Windows application shell

[blakinio]

Purpose

Implement the single authorized W4-SHELL package: one deterministic Windows blank-window application shell using merged foundation, diagnostics and test-support contracts.

Delivered contract

• exactly one oteryn-client package at oteryn-client/apps/client/, category app;
• exact direct winit = "=0.30.13", with generated lockfile and unchanged cargo-deny policy;
• ShellState, ShellPhase, ShellCommand, ShellError and WindowSnapshot;
• bounded transactional commands and 32-event structured lifecycle history;
• one main-thread ApplicationHandler creating one resizable blank window and enabling IME;
• one named one-shot oteryn-shell-wake thread, one proxy event and mandatory join after run_app;
• explicit automated PASS versus interactive BLOCKED evidence matrix.

Boundaries

No renderer/GPU, wgpu, direct raw-window-handle, direct windows-sys/Win32 FFI, unsafe, async runtime, executor, scheduler, protocol, identity, networking, assets, audio, feature UI, settings, persistence, updater, global logger or external-repository change.

No minimum-Windows, interactive DPI/IME/input, hardware or performance compatibility claim.

Task

OTC-20260729-windows-application-shell

Changed paths

Exactly twelve final owned/leased paths. All temporary branch-only bootstrap workflows were removed before final review.

Validation

Exact final head: 263aacf1e1440c26809620f1d0f37a42b0f3ec60.

Reviewed implementation head f5bb0fdda6c2555a6949f14d6afcc1edf843cfb9 passed:

• Rust Client run 30443333151: locked metadata, fmt, Clippy, eight tests, architecture and Supply Chain;
• repository CI run 30443331444: all required jobs and CI / Required;
• complete twelve-file path/full-diff review.

The final task-record head must pass the same exact-head graph before readiness/merge.

Runtime evidence

Named compile/test runner: Microsoft Windows Server 2025 Datacenter 10.0.26100, image windows-2025-vs2026 version 20260714.173.1.

Interactive visible launch/close, real resize/minimize/restore, multi-monitor DPI, physical input, real IME, shutdown/logoff and minimum Windows release remain BLOCKED, not inferred passes.