refactor: root-package imports (svc/runtime/interfaces) and fix PYTHONPATH

- Rename platform/ to svc/ to avoid shadowing stdlib platform.
- Replace from oclaw.* with from svc/runtime/interfaces; update -m CLI paths.
- tests/conftest: prepend repo root to sys.path (no parent-folder package name).
- CI: paths and offline_eval script under repo root.
- Ops scripts: PYTHONPATH must be repo root for python -m runtime.* (fixes gateway/WhatsApp sidecar startup).
- Fix default oclaw.json path in tabular/file attachment limits; stabilize attachment test config.

Co-authored-by: Cursor <cursoragent@cursor.com>

runtime/skills_workspace_lane.py

@@ -25,7 +25,7 @@ def skill_dir_private_lane_segment(skill_dir: str | Path, *, skills_home: Path |
 
     Flat ``_workspace/<skill>/`` (single segment) → ``None``.
     """
-    from oclaw.runtime.skills import default_skills_root
+    from runtime.skills import default_skills_root
 
     home = Path(skills_home).resolve() if skills_home else default_skills_root().resolve()
     ws = (home / "_workspace").resolve()
@@ -59,7 +59,7 @@ def resolve_auto_install_parent(
     - role installs: ``_workspace/<role>/`` (same level as ``public``, e.g. ``generalist``, ``ops``)
     - legacy session bucket: ``_workspace/_agent/<segment>/`` when no binding role is available
     """
-    from oclaw.runtime.skills import default_skills_root
+    from runtime.skills import default_skills_root
 
     base = Path(skills_home).resolve() if skills_home else default_skills_root().resolve()
     ws = base / "_workspace"