fix(dashboard): keep memory.provider in the config schema so Desktop's dropdown survives (#63886)

The dashboard's dedicated memory-provider UI (4b184cbe5) excluded
memory.provider from /api/config/schema server-side. Desktop's settings
page builds its field list from that schema, so the Memory Provider
dropdown silently vanished from Desktop after v0.18.1.

- web_server.py: restore memory.provider as a select in _SCHEMA_OVERRIDES,
  with options built from plugins.memory discovery (was a stale hardcoded
  [builtin, honcho] list before the removal)
- plugins/memory: add list_memory_provider_names() — directory-scan-only
  name listing, safe at module import time (no provider imports)
- web ConfigPage: hide memory.provider client-side instead — the Plugins
  page owns the dedicated provider-switching UI there
- tests: schema contract (select present, category memory, builtin
  sentinel) + invariant that every discoverable provider is selectable

hermes_cli/web_server.py

@@ -610,7 +610,30 @@ async def _token_auth_seam(request: Request, call_next):
 # ---------------------------------------------------------------------------
 
 # Manual overrides for fields that need select options or custom types
+def _memory_provider_options() -> List[str]:
+    """Discovered memory providers for the ``memory.provider`` select.
+
+    Directory-scan only (no provider imports), so it's safe at module import
+    time. ``""`` (built-in) is always first; discovery failures degrade to the
+    bundled defaults rather than dropping the field.
+    """
+    options = ["", "builtin"]
+    try:
+        from plugins.memory import list_memory_provider_names
+
+        options.extend(list_memory_provider_names())
+    except Exception:
+        options.extend(["honcho"])
+    # Dedupe, preserve order
+    return list(dict.fromkeys(options))
+
+
 _SCHEMA_OVERRIDES: Dict[str, Dict[str, Any]] = {
+    "memory.provider": {
+        "type": "select",
+        "description": "Memory provider plugin",
+        "options": _memory_provider_options(),
+    },
     "model": {
         "type": "string",
         "description": "Default model (e.g. anthropic/claude-sonnet-4.6)",
@@ -780,7 +803,7 @@ def _build_schema_from_config(
         full_key = f"{prefix}.{key}" if prefix else key
 
         # Skip internal / version keys
-        if full_key in {"_config_version", "memory.provider"}:
+        if full_key in {"_config_version"}:
             continue
 
         # Category is the first path component for nested keys, or "general"

plugins/memory/__init__.py

@@ -143,6 +143,17 @@ def find_provider_dir(name: str) -> Optional[Path]:
 # Public API
 # ---------------------------------------------------------------------------
 
+def list_memory_provider_names() -> List[str]:
+    """Cheap name-only listing of discoverable memory providers.
+
+    Unlike :func:`discover_memory_providers`, this does NOT import provider
+    modules or run availability checks — it's a directory scan only, safe to
+    call at module-import time (e.g. when building the dashboard config
+    schema).
+    """
+    return sorted({name for name, _ in _iter_provider_dirs()})
+
+
 def discover_memory_providers() -> List[Tuple[str, str, bool]]:
     """Scan bundled and user-installed directories for available providers.
 

tests/hermes_cli/test_web_server.py

@@ -3645,6 +3645,34 @@ class TestBuildSchemaFromConfig:
             assert "options" in entry
             assert "local" in entry["options"]
 
+    def test_memory_provider_field_present_as_select(self):
+        """memory.provider must stay in the config schema.
+
+        Desktop's settings page builds its field list from /api/config/schema —
+        a key excluded here silently vanishes from Desktop's Memory section
+        (regression: the dashboard's dedicated memory-provider UI excluded the
+        key server-side, breaking Desktop's dropdown). The dashboard hides the
+        field client-side instead.
+        """
+        from hermes_cli.web_server import CONFIG_SCHEMA
+        entry = CONFIG_SCHEMA["memory.provider"]
+        assert entry["type"] == "select"
+        assert entry["category"] == "memory"
+        options = entry["options"]
+        # Built-in sentinel first, plus at least one discovered provider.
+        assert options[0] == ""
+        assert "builtin" in options
+        assert len(options) >= 3
+
+    def test_memory_provider_options_cover_discovered_providers(self):
+        """Every provider the /api/memory endpoint can activate is selectable."""
+        from hermes_cli.web_server import CONFIG_SCHEMA
+        from plugins.memory import list_memory_provider_names
+
+        options = set(CONFIG_SCHEMA["memory.provider"]["options"])
+        missing = set(list_memory_provider_names()) - options
+        assert missing == set(), f"discovered providers missing from schema options: {missing}"
+
     def test_approvals_mode_options_match_config_values(self):
         """approvals.mode select options must match the values accepted by config.py.
 

web/src/pages/ConfigPage.tsx

@@ -169,7 +169,16 @@ export default function ConfigPage() {
     api
       .getSchema()
       .then((resp) => {
-        setSchema(resp.fields as Record<string, Record<string, unknown>>);
+        // memory.provider has a dedicated management UI on the Plugins page
+        // (provider cards + guided setup/switch flow). Hide it from the
+        // generic config form so the two surfaces don't fight; the schema
+        // keeps the field for other consumers (Desktop settings).
+        const fields = { ...resp.fields } as Record<
+          string,
+          Record<string, unknown>
+        >;
+        delete fields["memory.provider"];
+        setSchema(fields);
         setCategoryOrder(resp.category_order ?? []);
       })
       .catch(() => {});