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/orchestrator/__init__.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """DECNET orchestrator — synthetic life-injection worker.
 
 Drives realistic-looking activity between deckies (inter-decky traffic and

decnet/orchestrator/drivers/__init__.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Activity drivers for the orchestrator.
 
 Concrete drivers register dispatch in :func:`get_driver_for`.  Same

decnet/orchestrator/drivers/base.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Driver ABC for orchestrator actions.
 
 Each concrete driver (SSH, Email, future HTTP/SMB/MySQL) maps one

decnet/orchestrator/drivers/email.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Email driver — pluggable-LLM EML generation + decky-side delivery.
 
 One :class:`EmailAction` becomes one EML written into the mail decky's

decnet/orchestrator/drivers/smtp_relay.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """SMTP probe-relay driver.
 
 Forwards the attacker's first probe email via the master's real internet

decnet/orchestrator/drivers/ssh.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """MVP SSH-flavoured driver.
 
 Two action shapes:

decnet/orchestrator/emailgen/__init__.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Emailgen — email-specific delivery, scheduling, and threading.
 
 After stage 5 of the realism migration, ``emailgen`` is no longer a

decnet/orchestrator/emailgen/events.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """DB-row + bus-topic helpers for the emailgen worker.
 
 Mirror of :mod:`decnet.orchestrator.events` for the email action class.

decnet/orchestrator/emailgen/scheduler.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Action picker for the emailgen worker.
 
 One tick = one (mail-decky, sender, recipient, [thread]) decision.

decnet/orchestrator/emailgen/threads.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """RFC 2822 thread-chain bookkeeping.
 
 A thread is a worker-side UUID that groups one or more emails between

decnet/orchestrator/events.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """DB-row + bus-topic helpers for the orchestrator."""
 from __future__ import annotations
 

decnet/orchestrator/scheduler.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Action picker for the orchestrator.
 
 Stage-3 realism: file actions are sourced from

decnet/orchestrator/worker.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Orchestrator main loop.
 
 One tick = one action pick + one driver invocation + one DB write +