refactor(projects/sidebar): remove temp snapshot side-effects and simplify session metadata UX

Why this change was needed:
- Project listing had an implicit side effect: every fetch wrote a debug snapshot under `.tmp/project-dumps`.
  That added unnecessary disk I/O to a hot path, introduced hidden runtime behavior, and created maintenance
  overhead for code that was not part of product functionality.
- Keeping snapshot-specific exports/tests around made the projects module API broader than needed and coupled
  tests to temporary/debug behavior instead of user-visible behavior.
- Codex sessions could remain stuck with a placeholder name (`Untitled Codex Session`) even after a real title
  became available from newer sync data, which degraded session discoverability in the UI.
- Sidebar session rows showed duplicated provider branding and long-form relative times, which added visual noise
  and reduced scan speed when many sessions are listed.

What changed:
- Removed temporary projects snapshot dumping from `projects-with-sessions-fetch.service.ts`:
  - deleted snapshot types/helpers and file-write flow
  - removed the write call from `getProjectsWithSessions`
- Removed snapshot-related surface area from `projects/index.ts`.
- Removed the snapshot-focused test `projects.service.test.ts` that only validated removed debug behavior.
- Updated `codex-session-synchronizer.provider.ts` to upgrade session names when an existing session still has
  the placeholder title but a real parsed name is now available.
- Updated `SidebarSessionItem.tsx`:
  - removed duplicate provider logo rendering in each session row
  - moved age indicator to the right side
  - made age indicator fade on hover to prioritize action controls
  - switched to compact relative time format (`<1m`, `Xm`, `Xhr`, `Xd`) for faster list scanning

Outcome:
- Lower overhead and fewer hidden side effects in project fetches.
- Cleaner module boundaries in projects.
- Better Codex session naming consistency after sync.
- Cleaner sidebar density and clearer hover/action behavior.

server/modules/providers/list/codex/codex-session-synchronizer.provider.ts

@@ -42,6 +42,14 @@ export class CodexSessionSynchronizer implements IProviderSessionSynchronizer {
         continue;
       }
 
+      const existingSession = sessionsDb.getSessionById(parsed.sessionId);
+      if (existingSession) {
+        // If session name is untitled and we now have a name, update it
+        if (existingSession.custom_name === 'Untitled Codex Session' && parsed.sessionName && parsed.sessionName !== 'Untitled Codex Session') {
+          sessionsDb.updateSessionCustomName(parsed.sessionId, parsed.sessionName);
+        }
+      }
+
       const timestamps = await readFileTimestamps(filePath);
       sessionsDb.createSession(
         parsed.sessionId,