Sanitize codebase, reorganize docs, and add missing deploy files

Remove dead code identified in docs/SANITIZATION-REVIEW.md:
- app/blueprints/content_old.py and app/blueprints/playlist.py
- app/models/group.py, app/utils/nginx_config_reader.py
- orphaned templates (content_list, edit_content, upload_content,
  player_page) and the related group/Template references

Result: 6 blueprints, 82 routes, no dead modules or orphan templates.

Add files that deploy.sh and docker-entrypoint.sh already require but
which were never tracked:
- https_manager.py       (referenced by deploy.sh, migrate_network.sh,
                          docker-entrypoint.sh)
- Caddyfile.example      (seeded by deploy.sh; its absence aborts deploy)

Relocate generated Graphify artifacts from graphify-out/ to
docs/graphify-out/ (110 files, no content change) and archive the
superseded docs under docs/.

Ignore hygiene:
- ignore ad-hoc .env backups (.env.bak*) — they contain live secrets
- keep the pre-sanitization snapshots (docs/legacy code/,
  docs/old_code_documentation/) on disk but out of the repo

Fix .env.example: drop a duplicated config block, genericize the
hardcoded host IP, and document HOSTNAME_INTERNAL.

docs/01-architecture.md

@@ -56,7 +56,7 @@ Graphify assigns each node a **level** (0 = entry/global → 3 = utility):
 |---|---|---|
 | **L0 — Entry / Global** | 0 | `create_app()`, `app.py`, config classes, error handlers, CLI commands |
 | **L1 — Strategic / Core** | 1 | Blueprint route handlers (players, content, api, admin), model classes |
-| **L2 — Implementation** | 2 | Playlist/group management helpers, processing helpers, model methods |
+| **L2 — Implementation** | 2 | Playlist management helpers, processing helpers, model methods |
 | **L3 — Utility** | 3 | `logger.py`, `ssh_deploy.py`, `caddy_manager.py`, `uploads.py`, `pptx_converter.py`, migrations |
 
 ```mermaid
@@ -81,7 +81,6 @@ flowchart TD
         log["log_action()"]
         up["uploads.py"]
         pptx["pptx_converter.py"]
-        nginx["NginxConfigReader"]
     end
     create_app --> bp
     create_app --> models
@@ -102,14 +101,14 @@ Graphify clustered the code into **41 communities**. The 12 meaningful ones are
 
 | Community | Domain (derived) | Files | Role |
 |---|---|---|---|
-| **C0** (90) | **Authentication + legacy groups** | `blueprints/auth.py`, `blueprints/content_old.py`, `models/server_log.py`, `utils/logger.py`, `utils/group_player_management.py`, `old_code_documentation/blueprint_groups.py` | Auth flows + audit logging + (legacy) group features |
+| **C0** (90) | **Authentication + audit** | `blueprints/auth.py`, `models/server_log.py`, `utils/logger.py`, `old_code_documentation/blueprint_groups.py` | Auth flows + audit logging |
 | **C1** (80) | **Admin + HTTPS + player users** | `blueprints/admin.py`, `models/https_config.py`, `models/player_user.py`, `utils/caddy_manager.py`, `migrations/add_player_user_table.py` | Admin panel, Caddy HTTPS generation, editing-user registry |
 | **C2** (68) | **Playlist & content workflows** | `blueprints/content.py`, `blueprints/playlist.py`, `models/playlist.py` | Modern playlist-centric content management + legacy redirects |
 | **C3** (62) | **Player API + edits** | `blueprints/api.py`, `models/player_edit.py` | Player-facing REST, edited-media pipeline |
 | **C4** (55) | **Application core** | `app.py`, `config.py`, `models/user.py`, `utils/portal_sso.py`, `utils/script_name_fix.py` | App factory, config, auth identity, middleware |
 | **C5** (54) | **Content & player models** | `models/content.py`, `models/player.py`, `models/player_feedback.py`, `blueprints/main.py` | Media model, player model, feedback, dashboard |
 | **C6** (51) | **Player management UI** | `blueprints/players.py`, `migrations/add_https_config_table.py` | Player CRUD, manage page, deployment polling |
-| **C7** (42) | **Groups (legacy)** | `models/group.py`, `utils/nginx_config_reader.py` | Archived groups feature + legacy nginx reader |
+| **C7** (42) | ***(removed)*** | — | Groups model + legacy nginx reader were deleted during sanitization |
 | **C8** (24) | **Dev tooling** | `old_code_documentation/test_edit_media_api.py`, `Colors`, integrity checker | Test/analysis utilities |
 | **C9** (21) | **Upload processing** | `utils/uploads.py` | Upload progress, video/image processing |
 | **C10** (20) | **Deployment** | `utils/background_tasks.py`, `utils/ssh_deploy.py` | Background SSH deployment engine |