feat(bluesky): fix CORS by serving /config same-origin and pinning BAPP_CONFIG_URL

- Add `server.config_upstream_url` default in `roles/web-app-bluesky/config/main.yml`
  to define upstream for /config (defaults to https://ip.bsky.app/config).
- Introduce front-proxy injection `extra_locations.conf.j2` that:
  - proxies `/config` to the upstream,
  - sets SNI and correct Host header,
  - normalizes CORS headers for same-origin consumption.
- Wire the proxy injection only for the Web domain in
  `roles/web-app-bluesky/tasks/main.yml` via `proxy_extra_configuration`.
- Force fresh social-app checkout and patch
  `src/state/geolocation.tsx` to `const BAPP_CONFIG_URL = '/config'`
  in `roles/web-app-bluesky/tasks/02_social_app.yml`; notify `docker compose build` and `up`.
- Tidy and re-group PDS env in `roles/web-app-bluesky/templates/env.j2` (no functional change).
- Add vars in `roles/web-app-bluesky/vars/main.yml`:
  - `BLUESKY_FRONT_PROXY_CONTENT` (renders the extra locations),
  - `BLUESKY_CONFIG_UPSTREAM_URL` (reads `server.config_upstream_url`).

Security/Scope:
- Only affects the Bluesky web frontend (same-origin `/config`); PDS/API and AppView remain unchanged.

Refs:
- Conversation: https://chatgpt.com/share/68b8dd3a-2100-800f-959e-1495f6320aab

roles/web-app-bluesky/tasks/02_social_app.yml

@@ -3,6 +3,16 @@
     repo: "https://github.com/bluesky-social/social-app.git"
     dest: "{{ BLUESKY_SOCIAL_APP_DIR }}"
     version: "main"
+    force: true
   notify:
     - docker compose up
-    - docker compose build
+    - docker compose build
+
+- name: Force BAPP_CONFIG_URL to same-origin /config
+  ansible.builtin.replace:
+    path: "{{ BLUESKY_SOCIAL_APP_DIR }}/src/state/geolocation.tsx"
+    regexp: '^\s*const\s+BAPP_CONFIG_URL\s*=\s*.*$'
+    replace: "const BAPP_CONFIG_URL = '/config'"
+  notify:
+    - docker compose build
+    - docker compose up

roles/web-app-bluesky/tasks/main.yml

@@ -15,8 +15,9 @@
   include_role:
     name: sys-stk-front-proxy
   vars:
-    domain: "{{ BLUESKY_WEB_DOMAIN }}"
-    http_port: "{{ BLUESKY_WEB_PORT }}"
+    domain:                     "{{ BLUESKY_WEB_DOMAIN }}"
+    http_port:                  "{{ BLUESKY_WEB_PORT }}"
+    proxy_extra_configuration:  "{{ BLUESKY_FRONT_PROXY_CONTENT }}"
   when: BLUESKY_WEB_ENABLED | bool
 
 - name: "Include front proxy for {{ BLUESKY_VIEW_DOMAIN }}:{{ BLUESKY_VIEW_PORT }}"