feat: add host-local custom project icons (#2335)

* feat(projects): add local icons and colors

* refactor(projects): simplify appearance handling

* fix(projects): serialize appearance saves

* test(app): update project appearance expectations

* test: fix project appearance CI expectations

* refactor(projects): organize appearance code

* fix(server): adopt main's reconcile model in project appearance updates

* fix(projects): preserve host-local appearance targets

* fix(desktop): restore Linux development startup

Ubuntu can block Electron's unprivileged user-namespace fallback while the npm-installed sandbox helper is not SUID. Disable the Chromium process sandbox only in the Linux development runner so packaged desktop policy remains unchanged.

* feat(projects): add custom project icons

Keep URL acquisition in the client so the host daemon only validates uploaded bytes. Project name and icon changes share one adaptive edit sheet.

* refactor(settings): scope projects by host

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Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

docs/architecture.md

@@ -374,6 +374,7 @@ $PASEO_HOME/
 ├── agents/{cwd-with-dashes}/{agent-id}.json   # Agent record + persisted timeline rows
 ├── projects/projects.json                      # Project registry
 ├── projects/workspaces.json                    # Workspace registry
+├── projects/icons/                             # Custom project icon images
 ├── chat/                                       # Chat rooms
 ├── schedules/                                  # Scheduled-agent definitions and runs
 ├── loops/                                      # Loop runs and logs