feat: migrate secrets to Infisical

.env.example

@@ -1,3 +1,6 @@
+# Infisical secret inventory. This file contains names and safe defaults only;
+# the application does not load it. Store values under /app unless noted.
+
 # Server-only OpenAI access for the permission-gated ISAC mechanic and
 # calculation authoring assistants. Use a project-scoped, Responses-only restricted key.
 OPENAI_MECHANIC_API_KEY=
@@ -13,7 +16,8 @@ TDR_DATABASE_PATH=./data/shd-build-development.db
 # Persistent directory for normalized user-uploaded avatars.
 TDR_AVATAR_STORAGE_PATH=./data/avatars
 
-# Persistent directory for uploaded talent, brand, protocol, and skill-chip icons.
+# Persistent directory for game-data icons and managed library images, including
+# weapons, gear, mods, talents, brands, protocols, Skill Chips, and Specializations.
 TDR_GAME_ICON_STORAGE_PATH=./data/game-icons
 
 # Optional fixed credentials used only when initializing or explicitly resetting
@@ -25,6 +29,7 @@ DEFAULT_USER_PASSWORD=
 DISCORD_CLIENT_ID=
 DISCORD_CLIENT_SECRET=
 # Proxied development: https://dev.shd.build/auth/discord/callback
+# Staging: https://stage.shd.build/auth/discord/callback
 # Production: https://shd.build/auth/discord/callback
 DISCORD_REDIRECT_URI=https://dev.shd.build/auth/discord/callback
 
@@ -45,9 +50,14 @@ SMTP_USER=
 SMTP_PASSWORD=
 SMTP_FROM=SHD.build <no-reply@shd.build>
 
-# Long random bearer token used only by the internal container scheduler.
-SCHEDULER_TOKEN=
+# Cloudflare Turnstile challenge keys for anonymous Guide activity.
+TURNSTILE_SITE_KEY=
+TURNSTILE_SECRET_KEY=
+
 REMOVE_BG_API_KEY=
 REMOVE_BG_LOW_CREDIT_THRESHOLD=5
 REMOVE_BG_LOW_FREE_CALL_THRESHOLD=10
 REMOVE_BG_CREDIT_CHECK_HOURS=6
+
+# /shared/scheduler
+SCHEDULER_TOKEN=