fix(docker): create recordings directory with proper permissions

- Add recordings directory structure with .gitkeep, .gitignore, and README
- Update deployment script to set chmod 777 on recordings directory
- Fixes ENOENT/EACCES errors when discord-gateway tries to create user subdirectories
- Ensures container app user (UID 100) can write recording files

This resolves the crash on voice channel connection where the service
failed to create user-specific recording directories like:
- recordings/<user-id>/
- recordings/sessions/

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/deploy-docker.yml

@@ -94,6 +94,8 @@ jobs:
             cd "$APP_DIR"
 
             mkdir -p infra/docker/recordings
+            # Set permissions for recordings directory (writable by container app user UID 100)
+            chmod -R 777 infra/docker/recordings
             printf '%s\n' "$ENV_FILE" > infra/docker/.env
 
             echo "$GHCR_TOKEN" | docker login ghcr.io -u "$GHCR_USERNAME" --password-stdin

infra/docker/recordings/.gitignore

@@ -0,0 +1,3 @@
+*
+!.gitkeep
+!README.md

infra/docker/recordings/README.md

@@ -0,0 +1,15 @@
+# Recordings Directory
+
+This directory is mounted as a volume in the discord-gateway container.
+Voice recordings are stored here with the following structure:
+
+```
+recordings/
+  ├── <user-id>/
+  │   ├── <timestamp>.ogg
+  │   └── <timestamp>.json
+  └── sessions/
+      └── <session-id>.json
+```
+
+The directory must be writable by UID 1000 (app user in the container).