fix: preserve connection selection and repair terminal/cockpit regressions

[benfavre]

Filtered connection-picker clicks could choose an unrelated host when popup dismissal cleared the search before selection. SDPATCH-046 preserves the rendered original row identity for mouse selection, resolves keyboard focus to that same identity, and shows the committed selected label. Native testing verifies both the displayed label and persisted target UUID before executing.

The same QA pass fixes default-cleartext login/API-key inputs and squeezed API-key controls, uppercase/tag connection searches, request-sheet opening/closing focus, collapsed Platform/Agents searches, and inherited black labels on dark Workspace/Agents surfaces. Four failing terminal parser regressions cover malformed Unicode OSC colors, lost PTY replies and completion generations after RIS, and right-margin combining characters.

Two SSH-helper integration tests now run in child processes because their real descriptor-based cwd changes raced under parallel test execution.

Validation:

• 853 unique workspace tests passed; six infrastructure/live tests and two doc examples remain ignored.
• The SSH-helper group passed ten repeated parallel runs after isolating cwd.
• Linux debug build, workspace check, Clippy with --no-deps -- -D warnings, formatting and whitespace checks passed.
• Actual native Linux app exercised on private X11 at 1200 × 850 and 820 × 600 in Light/Tokyo Night, with fictional Manage data, local PTY/script execution, key-authenticated SSH to a disposable loopback server, and actual Local → Remote HTTP forwarding plus stop, remote script output/exit status, and secret-field masking/reveal/401 retry (also at 580 × 600).
• Dated feature coverage, remaining live gaps and original before/after screenshots.

Automated native focus/layout/event-order coverage remains explicitly Red in SDTEST-1930..1934. Production authentication, cloud mutations, paid/provider runs, update installation and native macOS/Windows interaction are not claimed as live-tested.