Prevent plugin command aliases from becoming prompts

Added focused Python-port regressions for plugin, plugins, marketplace, and reload-plugins command routing, execution, stream, and turn-loop paths; narrowed runtime routing to honor explicit leading commands before fuzzy inventory matches.

Constraint: Task 10 scope limited changes to tests/test_porting_workspace.py plus narrow src parser/runtime fixes only if required.

Rejected: Test-only coverage without alias routing fix | route /plugin previously preferred fuzzy AddMarketplace over exact plugin command.

Confidence: high

Scope-risk: narrow

Directive: Keep --no-plugin-commands excluding plugin source hints; do not reinterpret that intentional filter as fallthrough.

Tested: python3 -m unittest tests.test_porting_workspace; python3 -m compileall src tests/test_porting_workspace.py; CLI route/turn-loop/filter smoke for /plugin, /plugins, /marketplace, /reload-plugins.

Not-tested: Full repository non-Python/Rust suites.

src/runtime.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 from dataclasses import dataclass
 
-from .commands import PORTED_COMMANDS
+from .commands import PORTED_COMMANDS, get_command
 from .context import PortContext, build_port_context, render_context
 from .history import HistoryLog
 from .models import PermissionDenial, PortingModule
@@ -88,6 +88,7 @@ class RuntimeSession:
 
 class PortRuntime:
     def route_prompt(self, prompt: str, limit: int = 5) -> list[RoutedMatch]:
+        explicit_command = self._explicit_command_match(prompt)
         tokens = {token.lower() for token in prompt.replace('/', ' ').replace('-', ' ').split() if token}
         by_kind = {
             'command': self._collect_matches(tokens, PORTED_COMMANDS, 'command'),
@@ -95,6 +96,16 @@ class PortRuntime:
         }
 
         selected: list[RoutedMatch] = []
+        if explicit_command is not None:
+            selected.append(explicit_command)
+            by_kind['command'] = [
+                match
+                for match in by_kind['command']
+                if not (
+                    match.name == explicit_command.name
+                    and match.source_hint == explicit_command.source_hint
+                )
+            ]
         for kind in ('command', 'tool'):
             if by_kind[kind]:
                 selected.append(by_kind[kind].pop(0))
@@ -106,6 +117,22 @@ class PortRuntime:
         selected.extend(leftovers[: max(0, limit - len(selected))])
         return selected[:limit]
 
+    @staticmethod
+    def _explicit_command_match(prompt: str) -> RoutedMatch | None:
+        first_token = prompt.strip().split(maxsplit=1)[0] if prompt.strip() else ''
+        command_name = first_token.removeprefix('/')
+        if not command_name:
+            return None
+        module = get_command(command_name)
+        if module is None:
+            return None
+        return RoutedMatch(
+            kind='command',
+            name=module.name,
+            source_hint=module.source_hint,
+            score=100,
+        )
+
     def bootstrap_session(self, prompt: str, limit: int = 5) -> RuntimeSession:
         context = build_port_context()
         setup_report = run_setup(trusted=True)