fix(tier2): override MCP server path + reset mcp_paths.toml in clone

Follow-up to 9cd85364. The previous fix patched the OpenCode session-
level permission.read/write allowlist to include the sandbox clone
path, but Tier 2 was still hitting 'ACCESS DENIED' on clone paths.

Root cause: the MCP server has its OWN allowlist that's separate from
OpenCode's session-level permission. The MCP server's allowlist =
project_root (parent dir of the script) + extra_dirs from
mcp_paths.toml in the project root. The clone inherited the main
repo's mcp.manual-slop.command via 'git clone', which launched
C:\\projects\\manual_slop\\scripts\\mcp_server.py with
PYTHONPATH=C:\\projects\\manual_slop\\src. So the MCP server was
using the main repo's project_root + the main repo's mcp_paths.toml
(extra_dirs=['C:/projects/gencpp']) -- exactly the
'Allowed base directories are: gencpp, manual_slop' the user saw.

Fix: setup_tier2_clone.ps1 now overrides the clone's mcp.manual-slop
config to point at the CLONE's scripts/mcp_server.py and src/, and
replaces the clone's mcp_paths.toml with an empty extra_dirs list.
The MCP server's allowlist becomes [C:\\projects\\manual_slop_tier2]
only -- the sandbox boundary.

Added test_setup_script_overrides_mcp_server (text-based regression)
to assert the script contains the required overrides. Opt-in via
TIER2_SANDBOX_TESTS=1.

Verified: re-ran setup against the live clone. opencode.json now has
mcp.manual-slop.command pointing at C:\\projects\\manual_slop_tier2\\
scripts\\mcp_server.py with PYTHONPATH=C:\\projects\\manual_slop_tier2\\
src. mcp_paths.toml has 'extra_dirs = []'.

tests/test_tier2_setup_bootstrap.py

@@ -37,3 +37,18 @@ def test_bootstrap_whatif_does_not_create_clone(tmp_path: Path) -> None:
  assert result.returncode == 0, f"pwsh exit {result.returncode}\nstdout={result.stdout}\nstderr={result.stderr}"
  assert "What if" in result.stdout or "starting bootstrap" in result.stdout or "Bootstrap Tier 2 clone" in result.stdout
  assert not fake_clone.exists(), "-WhatIf should not have created the clone"
+
+
+def test_setup_script_overrides_mcp_server() -> None:
+ """Regression test: setup_tier2_clone.ps1 MUST override the MCP server's
+ command and PYTHONPATH to point at the Tier 2 clone, AND reset the
+ clone's mcp_paths.toml to empty extra_dirs. Otherwise the clone inherits
+ the main repo's MCP config (which has manual_slop's path and an
+ mcp_paths.toml allowlisting gencpp), leading to 'ACCESS DENIED' on clone
+ paths (2026-06-17 bug)."""
+ script = Path("scripts/tier2/setup_tier2_clone.ps1").resolve()
+ content = script.read_text(encoding="utf-8")
+ assert "mcp.'manual-slop'.command" in content, "script must override MCP server command"
+ assert "mcp.'manual-slop'.environment.PYTHONPATH" in content, "script must override MCP server PYTHONPATH"
+ assert "mcp_paths.toml" in content, "script must reset mcp_paths.toml"
+ assert "extra_dirs = []" in content, "script must set extra_dirs to empty"