feat: rootless podman, session hardening, boot stability, sidebar fix

Rootless podman migration (TASK-11):
- Remove sudo from all podman calls in PodmanClient + 8 backend files
- Remove sudo from all podman/docker calls in deploy script
- Restore full systemd security hardening: NoNewPrivileges,
  RestrictAddressFamilies, MemoryDenyWriteExecute, RestrictRealtime,
  RestrictNamespaces, RestrictSUIDSGID, SystemCallFilter, ProtectSystem=strict
- Enable loginctl linger for rootless container persistence
- Remove Ollama from auto-deploy (marketplace-only)

Session & auth hardening:
- Increase MAX_CONCURRENT_SESSIONS 20→50 (prevents eviction storms)
- Debounced 401 redirect in rpc-client.ts (prevents redirect storms)

Boot stability:
- optimize-debian.sh: adds chrony, swap, removes policy-rc.d
- deploy script: pre-restart chrony + swap setup
- ISO build: chrony package, swap file creation
- BootScreen: no longer clears localStorage (prevents splash replay)
- RootRedirect: sole owner of localStorage clearing on server ready

UI fixes:
- Sidebar opacity default changed from 0→visible (fixes missing sidebar
  after page-persistence login without entrance animation)
- Console.log/error wrapped in import.meta.env.DEV guards
- Remove unused route import from RootRedirect

Beta tracking:
- CLAUDE.md: beta freeze protocol added
- MASTER_PLAN.md: TASK-11, TASK-17, phase structure
- BETA-PROGRESS.md: initial tracking doc
- Tagged v1.2.0-alpha.1 as pre-rootless baseline

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

core/container/src/podman_client.rs

@@ -102,9 +102,9 @@ impl PodmanClient {
     }
 
     fn podman_async(&self) -> TokioCommand {
-        // Always use sudo podman to access system-wide containers
-        let mut cmd = TokioCommand::new("sudo");
-        cmd.arg("podman");
+        // Rootless podman: run as the current user (no sudo).
+        // Requires: loginctl enable-linger <user>, containers migrated to user storage.
+        let cmd = TokioCommand::new("podman");
         cmd
     }