chore: relicense to AGPL-3.0-or-later and add SPDX headers

Replaces LICENSE (GPLv3 -> AGPLv3) and prepends
`SPDX-License-Identifier: AGPL-3.0-or-later` to every source file
across decnet/, decnet_web/, tests/, scripts/, and tools/.

Rationale: closes the GPLv3 ASP loophole so any party operating a
modified DECNET as a network service must offer their modified
source. Personal copyright (Samuel Paschuan) + inbound=outbound
contributions make a future unilateral relicense infeasible.

- LICENSE: full AGPL-3.0 text (gnu.org/licenses/agpl-3.0.txt)
- COPYRIGHT: project copyright notice
- tools/add_spdx_headers.py: idempotent header injector
  (shebang- and PEP 263-aware)

Touches 1565 source files (.py, .ts, .tsx, .js, .jsx, .css, .sh).
No behavior change; comments only.

decnet/web/router/topology/__init__.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """MazeNET topology REST endpoints (phase 3).
 
 Thin FastAPI layer over the phase-2 topology machinery:

decnet/web/router/topology/_guards.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Shared helpers for the Phase-3 child-CRUD routes."""
 from __future__ import annotations
 

decnet/web/router/topology/_target_host.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Shared validation for the ``mode`` / ``target_host_uuid`` pair.
 
 Called by the two topology-create endpoints

decnet/web/router/topology/api_catalog.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Read-only catalog endpoints — services, next-subnet, next-ip.
 
 These wrap fleet/allocator helpers so the phase-4 canvas UI can lean

decnet/web/router/topology/api_create_blank_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST /topologies/blank — create an empty editable topology.
 
 Produces a minimal ``pending`` topology seeded with exactly one DMZ LAN

decnet/web/router/topology/api_create_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST /topologies — generate and persist a new MazeNET topology."""
 from __future__ import annotations
 

decnet/web/router/topology/api_decky_crud.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Decky CRUD endpoints — pending-only child mutations.
 
     POST   /topologies/{id}/deckies

decnet/web/router/topology/api_delete_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """DELETE /topologies/{id} — cascade-delete a pending or torn-down topology."""
 from __future__ import annotations
 

decnet/web/router/topology/api_deploy_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST /topologies/{id}/deploy — transition pending → deploying and fire
 the background deploy.
 

decnet/web/router/topology/api_edge_crud.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Edge CRUD endpoints — pending-only child mutations.
 
     POST   /topologies/{id}/edges

decnet/web/router/topology/api_events.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """SSE stream of topology lifecycle events — one connection per editor.
 
 Subscribes to ``topology.<id>.>`` on the :class:`~decnet.bus.base.BaseBus`

decnet/web/router/topology/api_get_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """GET /topologies/{id} and /topologies/{id}/status-events."""
 from __future__ import annotations
 

decnet/web/router/topology/api_lan_crud.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """LAN CRUD endpoints — pending-only child mutations.
 
     POST   /topologies/{id}/lans

decnet/web/router/topology/api_list_topologies.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """GET /topologies — paginated list of MazeNET topologies."""
 from __future__ import annotations
 

decnet/web/router/topology/api_mutations.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Live-mutation queue endpoints — for active | degraded topologies.
 
     POST /topologies/{id}/mutations   enqueue one mutation op

decnet/web/router/topology/api_personas.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """GET/PUT ``/topologies/{id}/personas`` — per-topology email persona pool.
 
 The global pool (``decnet/web/router/emailgen/api_personas.py``) drives

decnet/web/router/topology/api_reap_orphans.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST /topologies/reap-orphans — remove Docker resources for topology
 ids the DB no longer knows about.
 

decnet/web/router/topology/api_tarpit.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST/GET/DELETE /api/v1/topologies/{topology_id}/deckies/{decky_name}/tarpit
 
 Same tc netem logic as the fleet tarpit, but scoped to a MazeNET topology.

decnet/web/router/topology/api_teardown_topology.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """POST /topologies/{id}/teardown — transition an active/degraded/failed
 topology to ``tearing_down`` and fire the background teardown.