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>

agent_harness/persona.py

@@ -0,0 +1,39 @@
+"""Persona orientation via kaizen-agentic (ADR-005 prepare step).
+
+The ADR-005 contract for a scheduled run is `kaizen-agentic schedule
+prepare <agent>` executed against the target repo: it bundles the agent
+prompt, project memory, metrics summary, and repo pointers from local
+`.kaizen/` state — offline-safe, no hub required. The worker treats the
+bundle as orientation text prepended to the task prompt.
+
+Falls back to an empty bundle when the CLI or the repo's schedule state is
+absent, so a task can still run persona-less (logged in run metadata).
+"""
+
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+
+def load_persona_bundle(agent: str, target_repo: Path, timeout: int = 60) -> tuple[str, str]:
+    """Return (bundle_text, source) where source is 'prepare' or 'none'."""
+    try:
+        result = subprocess.run(
+            [
+                "kaizen-agentic",
+                "schedule",
+                "prepare",
+                agent,
+                "--target",
+                str(target_repo),
+            ],
+            capture_output=True,
+            text=True,
+            timeout=timeout,
+        )
+    except (FileNotFoundError, subprocess.TimeoutExpired):
+        return "", "none"
+    if result.returncode != 0 or not result.stdout.strip():
+        return "", "none"
+    return result.stdout, "prepare"