Anyone not signed in holds the guest role

Whether somebody with no account may see something was being answered one
feature at a time: a securesend_allow_guests setting, an enable flag per kiosk,
and very nearly a third for guides - each with its own settings page, its own
vocabulary and its own hand-written branch inside a route. Every one of them
answered a permissions question, and this app already administers permissions
per role.

So a caller with no token is not nobody: they hold the seeded `guest` role.
require_permission consults it when there is no identity, which is the entire
mechanism. The role is seeded holding NOTHING, so an upgrade opens no door; a
site opens one by ticking a box in the same grid it uses for every other role,
and closes it the same way. Revocation is read on every request rather than
cached, because taking guest access away is what somebody does the moment they
realise what they opened, and it has to bite immediately.

The redundant @jwt_required() above require_permission is gone from 184 routes.
It was belt-and-braces before; now it is actively wrong, because it refuses a
request with no token before the permission check can have an opinion, so a
grant would appear to do nothing.

What a guest may hold is bounded. Any .view or .read permission is grantable.
A WRITE has to be blessed by whoever owns it, through the new
get_guest_grantable_permissions hook (contract 0.21.0), and Secure Send is the
only case that exists: sending a password to a vendor is the one write this
product means to offer somebody who never signs in. Everything else is refused
by the API and greyed out in the grid rather than warned about - a checkbox
that quietly makes deleting an asset anonymous is not a warning anybody reads
twice. A guest write records no creator: the trail says when and from where,
never who, and that is the reason for the bar.

GE-Enforce and Slides gained read permissions so they can be opened to guests
without handing out the manage right. Their read routes accept either through
require_any_permission, so nothing an existing manager could reach has moved.

The navigation endpoint now returns only what the caller can actually reach.
Without that a signed-out visitor gets a sidebar of the whole app where every
link bounces off the login page, which reads as a broken site rather than as a
closed door. A nav item may name several permissions; holding any one is
enough, which is what GE-Enforce and Slides need now that a viewer and a
manager hold different strings.

Two things this found on the way: current_user is a LocalProxy, so
`current_user is None` is False for a request with nobody behind it - harmless
under a required JWT, an AttributeError the moment verification became
optional. And an image pasted into a guide before its first save was never
attached to it, so it was visible to editors and invisible to every reader;
saving now attaches it, and `flask guides fix-images` repairs what is stored.

The guides guest setting written earlier today is gone. Granting guides.view to
the guest role replaces it, which is the point.

plugins/printers/api/asset_routes.py

@@ -68,7 +68,6 @@ def get_printer_type(type_id: int):
 
 
 @printers_asset_bp.route('/types', methods=['POST'])
-@jwt_required()
 @require_permission('printers.create')
 def create_printer_type():
     """Create a new printer type."""
@@ -105,7 +104,6 @@ def create_printer_type():
 
 
 @printers_asset_bp.route('/types/<int:type_id>', methods=['PUT'])
-@jwt_required()
 @require_permission('printers.edit')
 def update_printer_type(type_id: int):
     """Update a printer type."""
@@ -129,7 +127,6 @@ def update_printer_type(type_id: int):
 
 
 @printers_asset_bp.route('/types/<int:type_id>', methods=['DELETE'])
-@jwt_required()
 @require_permission('printers.delete')
 def delete_printer_type(type_id: int):
     """Delete a printer type. Refused if any printer still uses it."""
@@ -161,7 +158,6 @@ def list_drivers():
 
 
 @printers_asset_bp.route('/drivers', methods=['POST'])
-@jwt_required()
 @require_permission('printers.create')
 def create_driver():
     data = request.get_json() or {}
@@ -180,7 +176,6 @@ def create_driver():
 
 
 @printers_asset_bp.route('/drivers/<int:driver_id>', methods=['PUT'])
-@jwt_required()
 @require_permission('printers.edit')
 def update_driver(driver_id):
     d = db.session.get(PrinterDriver, driver_id)
@@ -197,7 +192,6 @@ def update_driver(driver_id):
 
 
 @printers_asset_bp.route('/drivers/<int:driver_id>', methods=['DELETE'])
-@jwt_required()
 @require_permission('printers.delete')
 def delete_driver(driver_id):
     d = db.session.get(PrinterDriver, driver_id)
@@ -993,7 +987,6 @@ def get_asset_printer_assignment(asset_id: int):
 
 
 @printers_asset_bp.route('/assignments/for-asset/<int:asset_id>', methods=['PUT'])
-@jwt_required()
 @require_permission('printers.edit')
 def set_asset_printer_assignment(asset_id: int):
     """Reconcile one asset's whole printer assignment in a single call.
@@ -1498,7 +1491,6 @@ def _observed_host_block(hostname, asset, index):
 
 
 @printers_asset_bp.route('/observed/<hostname>', methods=['GET'])
-@jwt_required()
 @require_permission('printers.view')
 def observed_for_host(hostname: str):
     """What a host last reported, each queue judged against what it is assigned.
@@ -1536,7 +1528,6 @@ def observed_for_host(hostname: str):
 
 
 @printers_asset_bp.route('/observed/for-asset/<int:asset_id>', methods=['GET'])
-@jwt_required()
 @require_permission('printers.view')
 def observed_for_asset(asset_id: int):
     """The same comparison, reached from an asset page: one block per host.
@@ -1649,7 +1640,6 @@ def _seed_source_hostnames(asset):
 
 @printers_asset_bp.route('/assignments/seed-from-observed/<int:asset_id>',
                          methods=['POST'])
-@jwt_required()
 @require_permission('printers.edit')
 def seed_assignment_from_observed(asset_id: int):
     """Write what a PC observed as the assignment of the asset in the path.
@@ -1840,7 +1830,6 @@ def get_printer_by_asset(asset_id: int):
 
 
 @printers_asset_bp.route('', methods=['POST'])
-@jwt_required()
 @require_permission('printers.create')
 def create_printer():
     """
@@ -1944,7 +1933,6 @@ def create_printer():
 
 
 @printers_asset_bp.route('/<int:printer_id>', methods=['PUT'])
-@jwt_required()
 @require_permission('printers.edit')
 def update_printer(printer_id: int):
     """Update printer (both Asset and Printer records)."""
@@ -2031,7 +2019,6 @@ def update_printer(printer_id: int):
 
 
 @printers_asset_bp.route('/<int:printer_id>', methods=['DELETE'])
-@jwt_required()
 @require_permission('printers.delete')
 def delete_printer(printer_id: int):
     """Delete (soft delete) printer."""
@@ -2303,7 +2290,6 @@ def printer_lookup():
 
 
 @printers_asset_bp.route('/supplies/refresh', methods=['POST'])
-@jwt_required()
 @require_permission('printers.create')
 def refresh_supplies_cache():
     """Clear cached Zabbix supply data so the next read pulls fresh values.
@@ -2485,7 +2471,6 @@ def list_model_supplies(modelnumberid: int):
 
 
 @printers_asset_bp.route('/models/<int:modelnumberid>/supplies', methods=['POST'])
-@jwt_required()
 @require_permission('printers.create')
 def create_model_supply(modelnumberid: int):
     """Add a supply to a model."""
@@ -2526,7 +2511,6 @@ def create_model_supply(modelnumberid: int):
 
 
 @printers_asset_bp.route('/supplies/<int:modelsupplyid>', methods=['PUT'])
-@jwt_required()
 @require_permission('printers.edit')
 def update_model_supply(modelsupplyid: int):
     """Update a model supply."""
@@ -2571,7 +2555,6 @@ def update_model_supply(modelsupplyid: int):
 
 
 @printers_asset_bp.route('/supplies/<int:modelsupplyid>', methods=['DELETE'])
-@jwt_required()
 @require_permission('printers.delete')
 def delete_model_supply(modelsupplyid: int):
     """Delete a model supply."""
@@ -2615,7 +2598,6 @@ def _reordertip(supply):
 
 
 @printers_asset_bp.route('/dashboard/supplies', methods=['GET'])
-@jwt_required()
 @require_permission('printers.view')
 def dashboard_supplies():
     """Printers needing a cartridge, flattened to one row per printer.