fix(review-T17): apply review fixes B1/I1/I2/M1/M2 + T10+T15+any.nix+wsl cleanup

Review of dev vs 16644fc found 1 BLOCKING + 3 IMPORTANT + 2 MINOR.
All addressed in this commit:

B1 (R1.4 stale files in project-rules.md + AGENTS.md):
  Replaced 'vds/nginx.nix' (removed in ef38dc4) with 'home/termux.nix'
  (added in 958247b). R1.4 now correctly lists the 4 files that use
  100.64.0.0: home/termux.nix:256, modules/server/nextcloud.nix:73,
  modules/server/nginx.nix:109,253, modules/vds/systemd.nix:10.

I1 (count drift in '15 modules' docs):
  - AGENTS.md:84 + project-rules.md:97: '15 → 14' (with note that
    stirling-pdf was deleted in 5dd7a58)
  - manifest.json (T16): rewritten acceptance to '15 archived
    (13 from server/default.nix:37-50 + 2 from containers/ kokoro-tts
    and openhands) + 1 deleted (stirling-pdf) + 1 active (open-webui
    in containers/)'
  - modules/server/default.nix:37-50: comment now explains the
    three categories

I2 (T1 + T13 status stuck on pending):
  Both flipped to 'completed' in manifest.json. T1 import fix
  verified by nix eval (epral stateVersion = '24.05'). T13 done in
  61b3724 (nginx firewall rule removed). I3 (.ci/checks.sh committed)
  satisfied.

M1 (R1.3 stale nginx.nix:225 line number):
  Removed line number from both project-rules.md and AGENTS.md.
  Replaced with 'nginx.nix (networking.firewall)'.

M2 (R1.2 listed 7 services, 2 in archive):
  Updated to 12 actual services in both files. n8n and minecraft
  were archived in T16; they no longer need storage guard.

T10 (reality443Forwarding погашен):
  Removed option from options.nix:66-74, realityPorts from
  3x-ui.nix:33-35, and 'reality443Forwarding = true' from
  vds/default.nix:19. ADR-note comments left in place.

T15 (kokoro-tts and openhands archived):
  git mv modules/containers/kokoro-tts.nix → archive/containers/
  git mv modules/containers/openhands.nix → archive/containers/
  Also moved modules/containers/kokoro-tts/ (Dockerfile, app.py, etc.)
  to archive/containers/kokoro-tts/ for completeness.

any.nix (nix flake check support):
  Added stub fileSystems + boot.loader.grub to configurations/any.nix
  so 'nix flake check' can evaluate the 'default' template config
  (which is never deployed — real hosts have their own disko/grub).

wsl cleanup (dead imports blocking nix flake check):
  - Removed modules/wsl/containers/default.nix (was only imported
    nowhere, contained kokoro-tts reference)
  - Removed './containers' import from modules/wsl/default.nix
    (resolved to the now-removed default.nix)

nix flake check: previously failed with 'Path modules/containers does
not exist' (cached evaluation referenced old path). After this commit
the error is gone — flake check progressed past the path resolution
and started building derivations. Full build output not captured
(5-min timeout for download from cache.nixos.org), but path errors
are resolved.

T5 risk acknowledgment:
  .agent/decisions/0002-backups-external.md updated with explicit
  risk table for 'if no backups' scenario + ADR/R1.9 guidance.

T1, T2, T6, T7, T8, T9, T10, T12, T13, T15, T16, T17: all → completed
in manifest.json. T3, T4, T5, T11, T14: previously completed.
Remaining DEFERRED: T3 (otrecа SSH recovery), T5 (5.6 answer).

.pre-commit-config.yaml

@@ -0,0 +1,13 @@
+repos:
+  - repo: local
+    hooks:
+      - id: nixos-flake-checks
+        name: nixos flake invariant checks
+        description: |
+          Runs .ci/checks.sh: sops path_regex compliance, no
+          `:latest` in container images (with R1.5/R1.8 whitelist),
+          and `nix flake check` (skippable via --no-build).
+        entry: .ci/checks.sh --no-build
+        language: script
+        pass_filenames: false
+        always_run: true