fix(theme): guard color first paint and flatten composer fill

[pathscale]

Fixes the reported UI regressions and adds native outcome coverage for them.

Latest update:

• flat composer body with independently animated border
• working language selector
• correct color-wheel first paint and desktop placement
• dark-theme glass opacity and blur behavior
• theme-owned rem typography scaling, including XL
• restored project sidebar hide/show control
• stable interactive IDs plus static and live enforcement
• active-tab-first startup without eager pane hydration
• Codex Auto permission routing remains covered
• Debug builds report the locked resolved Rust dependency tree and installed UI version
• zsh-native QA runner and self-contained InlineEdit Escape scenario

Local results: 386 frontend tests, lint, typecheck and production build pass. Focused live native smoke passes color first-paint, language, composer fill and InlineEdit Escape. Full component sweep passes 72/72 in about 71 seconds. Merge after UI 2.11.9 and the native QA crate chain are published.

[pathscale]

Validation update:

• Fresh signed Experimental bundle built with tauri-runtime-blitz 0.1.16 and @pathscale/ui 2.11.8; dependency diagnostics verified the resolved sources.
• Owner build passed frontend checks, 304 GUI tests, signature verification, launch/render verification, and DOM-leak symbol verification.
• CI now installs published ps-qa 0.4.14.
• Exact focused CI order passes after retained-pane and nested-scroll isolation fixes.
• Fresh-profile native Blitz sweep passed 249/249 in 99.95s.
• Coverage includes pill shadow/hover/pointer selection, color-wheel first paint/layout, flat composer body, language selection, InlineEdit cancellation, independent Home/Recent pagers, update completion, Agent I/O controls, and destructive fixture isolation.