[codex] finish mvp handoff

[darwvin-dev]

Summary

• Finalizes the RemoteOpsX MVP handoff with persisted application settings, stable IPC error payloads, and rollback-safe frontend settings state.
• Adds Settings UI access from the top bar and command palette, applies theme settings, and wires the health refresh interval to persisted settings.
• Updates handoff documentation, roadmap notes, tests, and Graphify outputs.

Impact

• Users can now persist theme, default protocol ports, health refresh interval, retention, and desktop integration preferences.
• Backend validation now returns stable domain errors with safe internal-error redaction.
• The MVP is packaged and ready for manual desktop smoke testing before merge.

Validation

• npm test - 37 passed
• npm run build - passed
• cargo fmt --manifest-path src-tauri/Cargo.toml -- --check - passed
• cargo test --manifest-path src-tauri/Cargo.toml - 55 passed
• git diff --check - passed
• graphify update . - passed
• graphify cluster-only . --no-label - passed
• npm run app:build:arch - produced AppImage, deb, and rpm bundles

Manual follow-up

• Run npm run app:dev on a Linux desktop and smoke-test Settings open/save/restart persistence plus invalid-value rollback.

[darwvin-dev]

Follow-up fix pushed in 694bb90.\n\nWhat changed:\n- Fixed immediate SSH disconnect risk by giving every terminal connection generation its own backend PTY session id, so stale cleanup from React StrictMode/reconnect cannot close the new session.\n- Simplified the UI: removed decorative hero artwork, reduced gradients/shadows, tightened top bar/sidebar/dashboard spacing, removed the empty tab bar when no tabs are open, and fixed mobile horizontal overflow.\n\nValidation:\n- npm test: 38 passed\n- npm run build: passed\n- cargo fmt --manifest-path src-tauri/Cargo.toml -- --check: passed\n- cargo test --manifest-path src-tauri/Cargo.toml: 55 passed\n- git diff --check: passed\n- Playwright Vite render check: desktop and mobile not blank, no framework overlay, no horizontal overflow. Note: Vite browser mode shows expected Tauri invoke alerts because the Tauri runtime is unavailable outside the desktop shell.

[darwvin-dev]

SSH key install flow pushed in eab3b5a.\n\nWhat changed:\n- Added backend SSH key discovery from ~/.ssh with filtering for real private-key headers.\n- Added public-key resolution from adjacent .pub files, with ssh-keygen fallback when possible.\n- Added ssh_keys_list and ssh_key_install Tauri commands.\n- Added Server form key picker, manual path fallback, and explicit Install public key on server action.\n- Install copies only the public key into ~/.ssh/authorized_keys using an idempotent command; private keys are never copied to the server.\n\nValidation:\n- npm test: 38 passed\n- npm run build: passed\n- cargo fmt --manifest-path src-tauri/Cargo.toml -- --check: passed\n- cargo test --manifest-path src-tauri/Cargo.toml: 58 passed\n- git diff --check: passed\n- Playwright Vite modal check: Add Server modal renders, key path interaction reveals install action, desktop/mobile have no horizontal overflow.\n\nManual smoke still needed in Tauri shell: create/edit a server, select a key from ~/.ssh or enter a path, install public key, then connect with key auth.

[darwvin-dev]

First SSH connect race fixed in fa09080.\n\nRoot cause:\n- Previous fix separated sessions by tab generation, but React StrictMode remounts start from the same generation again.\n- The first mount cleanup could therefore close the remounted first SSH session with the same backend id.\n\nFix:\n- Added a monotonic connection attempt id and included it in the backend PTY session id: tab:generation:attempt.\n- Each spawn now has a unique backend id, so stale cleanup can only close its own old session.\n\nValidation:\n- npm test: 39 passed\n- npm run build: passed\n- cargo fmt --manifest-path src-tauri/Cargo.toml -- --check: passed\n- cargo test --manifest-path src-tauri/Cargo.toml: 58 passed\n- git diff --check: passed\n\nPlease retest first SSH connect in npm run app:dev. If it still fails, the terminal should now reflect the actual ssh/auth/server error instead of being killed by stale React cleanup.