feat: ACT/ECT strategy, package restructure, draft -01/-02 prep

Strategic work for IETF submission of draft-nennemann-act-01 and
draft-nennemann-wimse-ect-02:

Package restructure:
- move ACT and ECT refimpls to workspace/packages/{act,ect}/
- ietf-act and ietf-ect distribution names (sibling packages)
- cross-spec interop test plan (INTEROP-TEST-PLAN.md)

ACT draft -01 revisions:
- rename 'par' claim to 'pred' (align with ECT)
- rename 'Agent Compact Token' to 'Agent Context Token' (semantic
  alignment with ECT family)
- add Applicability section (MCP, OpenAI, LangGraph, A2A, CrewAI)
- add DAG vs Linear Delegation Chains section (differentiator vs
  txn-tokens-for-agents actchain, Agentic JWT, AIP/IBCTs)
- add Related Work: AIP, SentinelAgent, Agentic JWT, txn-tokens-for-agents,
  HDP, SCITT-AI-agent-execution
- pin SCITT arch to -22, note AUTH48 status

Outreach drafts:
- Emirdag liaison email (SCITT-AI coordination)
- OAuth ML response on txn-tokens-for-agents-06

Strategy document:
- STRATEGY.md with phased action plan, risk register, timeline

Submodule:
- update workspace/drafts/ietf-wimse-ect pointer to -02 commit

workspace/packages/act/tests/test_vectors.py

@@ -0,0 +1,35 @@
+"""Tests for act.vectors module — Appendix B test vectors."""
+
+import pytest
+
+from act.vectors import generate_vectors, validate_vectors
+
+
+class TestVectorGeneration:
+    def test_generates_15_vectors(self):
+        vectors, ctx = generate_vectors()
+        assert len(vectors) == 15
+
+    def test_vector_ids(self):
+        vectors, _ = generate_vectors()
+        ids = [v.id for v in vectors]
+        expected = [f"B.{i}" for i in range(1, 16)]
+        assert ids == expected
+
+    def test_valid_vectors_have_compact(self):
+        vectors, _ = generate_vectors()
+        for v in vectors:
+            if v.valid and v.id != "B.7":
+                assert v.compact, f"{v.id} should have compact"
+
+    def test_invalid_vectors_have_exception(self):
+        vectors, _ = generate_vectors()
+        for v in vectors:
+            if not v.valid:
+                assert v.expected_exception is not None, \
+                    f"{v.id} should have expected_exception"
+
+
+class TestVectorValidation:
+    def test_all_vectors_pass(self):
+        assert validate_vectors() is True