webapp: extract service layer (config.py + services/) from app.py

Phase 1a of a multi-session refactor toward a clean blueprint
structure. Pulls the helper code that lived alongside the routes in
the 1621-line app.py into focused modules. app.py is now 625 lines
of mostly routes plus a small Flask wiring header. Behaviour is
unchanged: smoke-tested against the 8 main GET routes (200 OK).

New modules:

- config.py            env vars + IMAGE_TYPES + FRIENDLY_NAMES +
                       SHARED_DEPLOY_* taxonomy + unattend XML
                       namespaces.
- services/audit.py    audit log file handler + audit() helper.
- services/csrf.py     session CSRF token + before_request validator
                       wired via init_csrf(app).
- services/fs.py       image_root / deploy_path / unattend_path /
                       control_path / tools_path + load_json /
                       save_json + resolve_destination.
- services/system.py   service_status / find_usb_mounts /
                       find_upload_sources.
- services/images.py   image_status + load_image_config.
- services/deploy.py   import_deploy + _merge_tree +
                       _replace_with_symlink + allowed_import_source.
- services/unattend.py parse_unattend / build_unattend_xml /
                       extract_form_data and the qn / qwcm / settings
                       pass helpers.
- services/wim.py      extract_startnet / update_startnet / list_files
                       wrapping wimextract / wimupdate / wimdir.

Endpoint names kept stable (dashboard, clonezilla_backups, etc.) so
existing url_for(...) calls in templates are unchanged. Phase 1b
(Flask blueprints with ".endpoint" naming) deferred to a future
session because it requires updating ~30 url_for sites in templates
and is mostly cosmetic.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

webapp/config.py

@@ -0,0 +1,66 @@
+"""Configuration constants for the PXE webapp.
+
+Reads from environment variables with sensible defaults that match the
+Ansible playbook's deploy paths. Also defines the canonical image type
+list and shared-directory taxonomy used by the import pipeline.
+"""
+
+import os
+
+# --- Filesystem paths --------------------------------------------------------
+SAMBA_SHARE = os.environ.get("SAMBA_SHARE", "/srv/samba/winpeapps")
+CLONEZILLA_SHARE = os.environ.get("CLONEZILLA_SHARE", "/srv/samba/clonezilla")
+BLANCCO_REPORTS = os.environ.get("BLANCCO_REPORTS", "/srv/samba/blancco-reports")
+ENROLLMENT_SHARE = os.environ.get("ENROLLMENT_SHARE", "/srv/samba/enrollment")
+UPLOAD_DIR = os.environ.get("UPLOAD_DIR", "/home/pxe/image-upload")
+SHARED_DIR = os.path.join(SAMBA_SHARE, "_shared")
+WEB_ROOT = os.environ.get("WEB_ROOT", "/var/www/html")
+BOOT_WIM = os.path.join(WEB_ROOT, "win11", "sources", "boot.wim")
+AUDIT_LOG = os.environ.get("AUDIT_LOG", "/var/log/pxe-webapp-audit.log")
+
+# --- Flask -------------------------------------------------------------------
+FLASK_SECRET_KEY = os.environ.get("FLASK_SECRET_KEY", "pxe-manager-dev-key-change-in-prod")
+MAX_CONTENT_LENGTH = 16 * 1024 * 1024 * 1024  # 16 GB max upload
+
+# --- Image taxonomy ----------------------------------------------------------
+# Subdirs inside Deploy/ shared across ALL image types.
+SHARED_DEPLOY_GLOBAL = ["Out-of-box Drivers"]
+
+# Subdirs inside Deploy/ shared within the same image family (by prefix).
+SHARED_DEPLOY_SCOPED = {
+    "gea-": ["Operating Systems", "Packages"],
+    "ge-":  ["Operating Systems", "Packages"],
+}
+
+# Sibling dirs at image root shared within the same image family.
+SHARED_ROOT_DIRS = {
+    "gea-": ["Sources"],
+    "ge-":  ["Sources"],
+}
+
+IMAGE_TYPES = [
+    "gea-standard",
+    "gea-engineer",
+    "gea-shopfloor",
+    "gea-shopfloor-mce",
+    "ge-standard",
+    "ge-engineer",
+    "ge-shopfloor-lockdown",
+    "ge-shopfloor-mce",
+]
+
+FRIENDLY_NAMES = {
+    "gea-standard": "GE Aerospace Standard",
+    "gea-engineer": "GE Aerospace Engineer",
+    "gea-shopfloor": "GE Aerospace Shop Floor",
+    "gea-shopfloor-mce": "GE Aerospace Shop Floor MCE",
+    "ge-standard": "GE Legacy Standard",
+    "ge-engineer": "GE Legacy Engineer",
+    "ge-shopfloor-lockdown": "GE Legacy Shop Floor Lockdown",
+    "ge-shopfloor-mce": "GE Legacy Shop Floor MCE",
+}
+
+# --- Unattend XML namespaces -------------------------------------------------
+UNATTEND_NS = "urn:schemas-microsoft-com:unattend"
+WCM_NS = "http://schemas.microsoft.com/WMIConfig/2002/State"
+NSMAP = {None: UNATTEND_NS, "wcm": WCM_NS}