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.

tests/cli/__init__.py

@@ -0,0 +1 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later

tests/cli/test_cli.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """
 Tests for decnet/cli.py — CLI commands via Typer's CliRunner.
 """

tests/cli/test_cli_db_reset.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """
 Tests for the `decnet db-reset` CLI command.
 

tests/cli/test_cli_service_pool.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """
 Tests for the CLI service pool — verifies that --randomize-services draws
 from all registered services, not just the original hardcoded 5.

tests/cli/test_embedded_workers.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """
 Regression guards for workers that duplicate standalone daemons.
 

tests/cli/test_gating_ttp_agent.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Agent-mode gating for the `ttp` worker (DEBT-047).
 
 `decnet ttp` runs the live TTP-tagging worker against local bus events

tests/cli/test_init.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """Orchestration tests for ``decnet init``.
 
 The command is a thin orchestrator over privileged system calls.  We

tests/cli/test_mode_gating.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """CLI mode gating — master-only commands hidden when DECNET_MODE=agent."""
 from __future__ import annotations
 

tests/cli/test_realism_gating.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """``decnet realism`` is master-only.
 
 Two layers per CLAUDE.md:

tests/cli/test_realism_import_personas.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """``decnet realism import-personas`` CLI command."""
 from __future__ import annotations
 

tests/cli/test_web_proxy_target.py

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
 """The web dashboard proxy must follow DECNET_API_HOST.
 
 Hardcoding 127.0.0.1 broke deploys where the operator binds the API to