Enable anonymous downloads on the host and harden Strings.fmt

Host (applied with root@192.168.88.30)
- [service] REQUIRE_SIGNIN_VIEW = false in /etc/gitea/app.ini (backup written
  alongside), Gitea restarted. Verified anonymously: repo page 200, API 200, and a
  release asset downloads at full size (50.8 MB AppImage).

Localization safety (Open Polish)
- Strings.placeholder_count() counts conversions and ignores %% escapes.
- Strings.fmt() validates the count and fails safe (warns, returns the template)
  instead of raising an engine error when a key's placeholders drift.
- Strings.validate() lints the table for a trailing %, unsupported conversions, and
  mixed positional/sequential placeholders.
- Tests cover the counter, the fail-safe path, a clean table, and a formatting pass
  over every placeholder key with type-correct arguments.

Docs
- TODO: distribution, release-pipeline, and open-polish sections are complete and
  moved to DONE; the v0.2.4-v0.2.8 backfill is closed as superseded.
- README/MEMORY updated. Version 0.2.14.

project.godot

@@ -8,7 +8,7 @@ config_version=5
 
 config/name="Step Line"
 config/description="Workplace security simulation about observation, access verification, and proportionate escalation."
-config/version="0.2.13"
+config/version="0.2.14"
 run/main_scene="res://scenes/main.tscn"
 config/features=PackedStringArray("4.3", "GL Compatibility")