v0.82.0: gate FileBrowser recreate on actual change (F2); drop unused restic binary (F1)

syncFileBrowserMounts no longer force-recreates FileBrowser unconditionally:
captures config.yaml+compose before writes, re-reads final content after, and
recreates only when they actually changed (new pure helper fbNeedsRecreate).
Controller restarts / no-op storage syncs now issue a plain up -d and do NOT
bounce the customer's file UI. Restore-mode DB reset still forces a recreate.

Dockerfile: removed the unused restic apt package (disk-tier restic moved to the
host agent; no controller code execs the binary). ResticSchedule/migrateResticToRsync
config+settings paths untouched (still live in the dashboard).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FpBYrZCt9sFDqLgbG5GRGD

controller/Dockerfile

@@ -39,7 +39,6 @@ FROM debian:bookworm-slim
 # Install runtime dependencies:
 # - docker-cli: for "docker compose" commands
 # - ca-certificates: for HTTPS (healthchecks pings, git)
-# - restic: for backup operations
 # - postgresql-client: for pg_dump
 # - default-mysql-client: for mysqldump
 # - sqlite3: for SQLite backup
@@ -55,7 +54,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     curl \
     gnupg \
     git \
-    restic \
     postgresql-client \
     default-mysql-client \
     sqlite3 \