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superseded docs under docs/.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/graphify-out/wiki/Community_1.md

@@ -0,0 +1,69 @@
+# Community 1
+
+> 80 nodes · cohesion 0.04
+
+## Key Concepts
+
+- [PlayerUser](file:///home/scheianu/digiserver-v2/app/models/player_user.py#L7) (74 connections)
+- [CaddyConfigGenerator](file:///home/scheianu/digiserver-v2/app/utils/caddy_manager.py#L36) (31 connections)
+- [admin.py](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1) (31 connections)
+- [get_config()](file:///home/scheianu/digiserver-v2/app/models/https_config.py#L43) (8 connections)
+- [build_player()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1028) (7 connections)
+- [update_https_config()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L886) (7 connections)
+- [https_config_status()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L995) (5 connections)
+- [caddy_manager.py](file:///home/scheianu/digiserver-v2/app/utils/caddy_manager.py#L1) (5 connections)
+- [create_user()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L79) (4 connections)
+- [https_config()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L856) (4 connections)
+- [_player_build_meta_path()](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1019) (4 connections)
+- [Admin blueprint for user management and system settings.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1) (4 connections)
+- [Path to the persisted player-build settings (in the instance folder).](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1020) (4 connections)
+- [Display the 'Build player files for deployment' admin page.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L1029) (4 connections)
+- [Change user role between user and admin.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L126) (4 connections)
+- [Delete a user account.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L160) (4 connections)
+- [Change application theme.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L188) (4 connections)
+- [Decorator to require admin role for route access.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L19) (4 connections)
+- [Upload custom logo for application.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L212) (4 connections)
+- [Clear all server logs.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L254) (4 connections)
+- [Display user management page.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L274) (4 connections)
+- [Get system information as JSON.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L323) (4 connections)
+- [Display leftover media files not assigned to any playlist.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L355) (4 connections)
+- [Display admin panel with system overview.](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L36) (4 connections)
+- [Delete all leftover images that are not part of any playlist](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py#L407) (4 connections)
+- *... and 55 more nodes in this community*
+
+## Class Diagram
+
+```mermaid
+classDiagram
+    class CaddyConfigGenerator {
+        +caddy_manager.py()
+    }
+    class PlayerUser {
+        +player_user.py()
+        +.__repr__()
+        +.to_dict()
+    }
+```
+
+## Relationships
+
+- No strong cross-community connections detected
+
+## Source Files
+
+- [/home/scheianu/digiserver-v2/app/blueprints/admin.py](file:///home/scheianu/digiserver-v2/app/blueprints/admin.py)
+- [/home/scheianu/digiserver-v2/app/models/https_config.py](file:///home/scheianu/digiserver-v2/app/models/https_config.py)
+- [/home/scheianu/digiserver-v2/app/models/player_edit.py](file:///home/scheianu/digiserver-v2/app/models/player_edit.py)
+- [/home/scheianu/digiserver-v2/app/models/player_user.py](file:///home/scheianu/digiserver-v2/app/models/player_user.py)
+- [/home/scheianu/digiserver-v2/app/utils/caddy_manager.py](file:///home/scheianu/digiserver-v2/app/utils/caddy_manager.py)
+- [/home/scheianu/digiserver-v2/migrations/add_player_user_table.py](file:///home/scheianu/digiserver-v2/migrations/add_player_user_table.py)
+
+## Audit Trail
+
+- EXTRACTED: 156 (41%)
+- INFERRED: 229 (59%)
+- AMBIGUOUS: 0 (0%)
+
+---
+
+*Part of the graphify knowledge wiki. See [[index]] to navigate.*