V2(ui): progressively harmonize the CodeNomad interface - #667

Introduce independent System, Light, CodeNomad Classic, Basalt, Fjord, Lichen, Velvet, Ember, and Custom schemes backed by the existing server-owned UI preferences.

Apply the selected palette before rendering and propagate ten validated core colors through semantic CSS variables and SUID. Preserve the exact current dark appearance through CodeNomad Classic, keep a custom draft across preset switches, and serialize rapid persistence writes while retaining instant local feedback.

Add a square, responsive settings selector and ten-color custom editor in all supported locales. Reject malformed colors and palettes that fail text, accent, or status contrast requirements.

Validated with the UI typecheck, production UI build, focused node tests, diff checks, and browser renders for System, Fjord, Classic, and Custom states.

Unify tabs, selectors, panels, messages, tool output, timeline, notification history, and settings around the shared square-corner token and window utility layers. Keep responsive layouts usable and expose toggle, focus, timestamp, and resize state consistently to assistive technology.

Add the host-neutral Preferences renderer, native titlebar controls, contextual provider routing, serialized dirty-state confirmation, and locale-complete labels. Keep the isolated renderer outside client-state authority and hide startup-only state there.

Cover native request parsing, dirty confirmation serialization, theme migration/reactivity, model visibility, runtime context, and virtual follow behavior. Validated with the 643-test UI suite, UI typecheck, and production build.

Run open_preferences_window through Tauri's asynchronous command executor so WebviewWindowBuilder can create the standalone window without blocking native IPC. This prevents fresh WebView2 profiles from stalling on about:blank and keeps later native commands responsive.

Validated with all 137 Tauri unit tests, a release build, and a cold-profile CDP check that loaded Advanced Preferences and the Developer Automation card.

Integrate the persistent Developer Mode runtime while preserving the standalone Preferences security boundary and harmonized desktop UI. Developer Mode remains available only to trusted local windows; Preferences keeps its constrained settings authority.

Remove the superseded Developer Run APIs, retain Preferences IPC and frameless lifecycle behavior, harden closed-window identifier cleanup, and regenerate the Tauri ACL schemas from the merged capabilities.

Validated with UI and Electron typechecks, 184 Electron native tests, 135 Tauri tests, Rust formatting, and generated-schema checks.

Move color schemes to the end of General settings and present every built-in and saved palette as a compact row with directly editable semantic color swatches. Saving prompts for an incremented preset name, validates contrast, and keeps unsaved edits behind the existing settings discard guard.

Persist palette selection and named presets in device UI state while retaining read fallback from the previous UI config location. Compact configured provider cards without removing model or disconnect actions, and remove redundant Agent and Model labels from assistant metadata.

Add preset normalization and naming coverage. Validated with the UI TypeScript check, focused Node tests, and the production UI build.

Restore the singleton Preferences window under Tauri Developer Mode by applying the shared WebView2 arguments to its webview and recovering stale window handles. The YOLO switch now uses the palette's dedicated session accent.

Protect unsaved palette edits across row changes, expose palette descriptions as native tooltips, and surface the 50-preset limit consistently on write. Simplify remaining agent/model metadata and keep provider identifiers readable in RTL layouts.

Validated with the UI typecheck and production build, palette/theme node tests, Rust Preferences tests, and cargo fmt.