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>

docs/MASTER_PLAN.md

@@ -20,6 +20,7 @@
 | **TASK-10** | **ISO build verification + multi-hardware test** | **P1** | PLANNED | - |
 | **TASK-11** | **Rootless podman + restore security hardening** | **P1** | PLANNED | - |
 | **TASK-12** | **Beta telemetry — node reporting + monitoring panel** | **P1** | PLANNED | - |
+| **TASK-17** | **Alpha version tags + rollback strategy** | **P2** | PLANNED | - |
 
 ### Phase 2: User Testing (controlled, real hardware)
 
@@ -181,6 +182,22 @@ Migrate from `sudo podman` (root containers) to rootless podman so the systemd s
 
 ---
 
+### TASK-17: Alpha version tags + rollback strategy (PLANNED)
+**Priority**: P2 — Medium
+**Status**: PLANNED (2026-03-18)
+
+Tag every significant alpha version with git tags for easy rollback. Each tag should correspond to a deployable state. Maintain a version log so any alpha can be rebuilt and deployed.
+
+**Tasks**:
+- [ ] Tag current state as `v1.2.0-alpha.1` (pre-rootless-podman)
+- [ ] Establish naming convention: `v{major}.{minor}.{patch}-alpha.{build}`
+- [ ] Tag after rootless podman migration: `v1.2.0-alpha.2`
+- [ ] Document rollback procedure (git checkout tag + deploy)
+- [ ] Add version tag step to deploy script (auto-tag on successful deploy)
+- [ ] Update CHANGELOG.md with each alpha milestone
+
+---
+
 ## Post-Beta (FROZEN)
 
 *These tasks are deferred until after beta ships. Do not start.*