feat(05-04): surface MCP caps in supamem doctor with provenance

- Add 'MCP caps' section to run_doctor between Config chain and
  Installed clients (D-12). Renders all three cfg.mcp_caps_* values
  with their chain.mcp_caps_* source attribution via console.py
  exports (ok()) — no bare print().
- Extend tests/test_cli_smoke.py with test_doctor_shows_caps that
  asserts the section header, all three keys, all three defaults
  (25/250/200), and the [source: ...] provenance tag. Uses the
  shared _run() helper that pins NO_COLOR=1, TERM=dumb, COLUMNS=200
  so Rich color escapes never pollute assertion strings.

Author: dzmitrys-dev

src/supamem/doctor.py

@@ -140,6 +140,22 @@ def run_doctor(*, redact_secrets: bool = True) -> int:
     # rich's soft_wrap still respects the 80-col default in pytest.
     print(format_chain(cfg, chain, redact_secrets=redact_secrets))
 
+    # ── Section 2b: MCP caps (D-12) ──────────────────────────────────────
+    console.print()
+    console.print("[supamem.brand]MCP caps[/supamem.brand]")
+    ok(
+        f"max_top_k         = {cfg.mcp_caps_max_top_k}  "
+        f"[source: {chain.mcp_caps_max_top_k}]"
+    )
+    ok(
+        f"max_query_chars   = {cfg.mcp_caps_max_query_chars}  "
+        f"[source: {chain.mcp_caps_max_query_chars}]"
+    )
+    ok(
+        f"max_preview_chars = {cfg.mcp_caps_max_preview_chars}  "
+        f"[source: {chain.mcp_caps_max_preview_chars}]"
+    )
+
     # ── Section 3: Installed clients drift ───────────────────────────────
     console.print()
     console.print("[supamem.brand]Installed clients[/supamem.brand]")

tests/test_cli_smoke.py

@@ -66,6 +66,27 @@ def test_index_runs_failsoft_with_no_sources() -> None:
     )
 
 
+def test_doctor_shows_caps() -> None:
+    """Plan 05-04 Task 01: ``supamem doctor`` surfaces the three cap values + sources.
+
+    Asserts the new "MCP caps" section renders with all three keys and their
+    defaults (25 / 250 / 200) plus a ``[source: ...]`` provenance tag. Subprocess
+    env is pinned by ``_run`` (NO_COLOR=1, TERM=dumb, COLUMNS=200) so Rich color
+    escapes never pollute the assertion strings.
+    """
+    result = _run("doctor")
+    # doctor exits 1 when Qdrant is unreachable (CI / dev without docker up);
+    # the caps section runs unconditionally before that exit, so we don't gate
+    # on returncode here — only on the rendered surface.
+    out = result.stdout
+    assert "MCP caps" in out, f"expected 'MCP caps' section header in output, got: {out!r}"
+    for key in ("max_top_k", "max_query_chars", "max_preview_chars"):
+        assert key in out, f"expected {key!r} in doctor output, got: {out!r}"
+    for default in ("25", "250", "200"):
+        assert default in out, f"expected default {default!r} in doctor output, got: {out!r}"
+    assert "[source:" in out, f"expected provenance tag '[source: ...]' in output, got: {out!r}"
+
+
 def test_version_prints_current() -> None:
     """Test 6: --version prints styled banner with current __version__ + credit line."""
     from supamem import __version__