Harness foundation: INTENT, ADR-001, architecture, prototype adoption

- INTENT.md: three-layer model (blueprint/instance/harness), single
  shared runtime, never-become boundaries
- ADR-001 (accepted): DEC-2026-002 resolution — one harness repo for
  all projects; instances are declarative state in consuming repos
- docs/architecture.md: components, contracts (manifest, tool
  profiles, completion events, credential lanes), deployment shape
- agent_harness/: executor-worker prototype adopted and renamed
  (6/6 tests green); HARNESS-WP-0001 initial workplan (7 tasks)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

pyproject.toml

@@ -0,0 +1,25 @@
+[project]
+name = "agent-harness"
+version = "0.1.0"
+description = "Thin executor worker: consumes emitted activity-core tasks and executes them via llm-connect adapters with kaizen persona orientation"
+requires-python = ">=3.11"
+dependencies = [
+    "httpx>=0.27",
+]
+
+[project.scripts]
+agent-harness = "agent_harness.cli:main"
+
+[tool.uv.sources]
+llm-connect = { path = "../llm-connect", editable = true }
+
+[project.optional-dependencies]
+llm = ["llm-connect"]
+dev = ["pytest>=8"]
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.wheel]
+packages = ["agent_harness"]