fix(s31): close 1 review BLOCKER — refuse --semantic-retrieval when it cannot take effect

src/portfolio_optimiser/run.py

@@ -859,6 +859,33 @@ def main(argv: list[str] | None = None) -> int:
         )
         return 1
 
+    # --semantic-retrieval is refused, never silently ignored (the repo's flag contract). In
+    # single-project mode it can only do observable work with BOTH of these: the Step-1 fold is
+    # gated on ``bundle_dir``, and ``--verdict-dir`` is the only route by which ``main()`` can hand
+    # ``run_project`` a non-empty store (``main()`` never passes ``store=``, and ``run_project``
+    # never seeds one). Without them the flag would rank nothing that reaches a prompt, and
+    # ``RunResult.retrieved`` never leaves the process — ``main()`` prints one outcome line only.
+    #
+    # DELIBERATELY STATIC. There is no runtime "refuse if the store ends up empty" check: a
+    # missing, empty or partially-skipped inbox is the Steg-7 tolerant-load contract, so refusing
+    # there would fire on a legitimate first run. The refusal is therefore necessary, not
+    # sufficient — it catches the configuration that CANNOT work, not every run that finds nothing.
+    #
+    # main() only. As a library API, ``run_project(semantic_retrieval=True, store=…)`` with a
+    # caller-supplied store stays legitimate — that is the path the tests drive. Portfolio mode is
+    # unaffected: ``run_portfolio`` always resolves a store and populates it by cross-project capture.
+    if args.semantic_retrieval:
+        required = {"--bundle-dir": args.bundle_dir, "--verdict-dir": args.verdict_dir}
+        missing = [name for name, value in required.items() if not value]
+        if missing:
+            print(
+                f"run refused: --semantic-retrieval requires {' and '.join(missing)} in "
+                "single-project mode (the Step-1 fold is bundle-path-only, and --verdict-dir is "
+                "the only route to a non-empty store)",
+                file=sys.stderr,
+            )
+            return 1
+
     if args.live_dry_run:
         # S4.2 drill (comparison protocol §4 pkt 2/3): walk the offline path, STOP before the first
         # model call, print the run-config. A misconfigured profile (e.g. AZURE with a