refactor(model-pool): scope disabled-models by company; cascade on delete (v42)

The per-connector "enabled/disabled model" settings lived under a
global key in the settings key-value table
(`disabled_models:${connectorId}`). No company dimension. Deleting a
company left the pool choices behind, and creating a new company
silently inherited them — the visible symptom was "onboarding's team-
model configuration survives company deletion and pollutes the next
company's CEO model list."

Root fix, not a cleanup hook: the storage becomes a real relational
table with `(company_id, connector_id)` primary key and an
`ON DELETE CASCADE` FK from `companies`. Company deletion wipes pool
config by construction; no cleanup step in `deleteCompany()` can
drift.

Schema (migration v42):
- CREATE TABLE connector_model_pool_settings (company_id, connector_id,
  disabled_models_json, updated_at), PK (company_id, connector_id),
  FK companies(id) ON DELETE CASCADE.
- Drop every `settings.disabled_models:*` key — these were the bug's
  residue; there is no right company to attribute them to, so the
  migration clears them. Users re-select on next onboarding.

API surgery — every reader/writer now takes companyId:
- db.getDisabledModels(companyId, connectorId)
- db.setDisabledModels(companyId, connectorId, models)
- db.hasModelPoolSettings(companyId, connectorId)
- connector-model-policy: getConnectorModelPolicy(deps, companyId,
  connectorId); validateConnectorModelSelection(deps, companyId,
  connectorId, model)
- model-dispatch: listEnabledModels(companyId, deps);
  pickModelForAgent resolves companyId from agent.companyId
- orchestration heartbeat/task-runner/turn-context/run-dispatch pass
  the agent's or run's companyId through to the policy deps
- IPC schema: connectorDisabledModelsSchema gains companyId; new
  connectorModelPoolQuerySchema pairs companyId+connectorId for reads

Onboarding becomes commit-on-launch:
- useConnectorModelSelection no longer persists via IPC during
  onboarding. Toggles mutate local state; it exposes `poolSelections`
  to the wizard.
- bootstrapOnboardingSchema gains connectorPoolSelections. The
  onboarding service saves the company first, then persists each
  per-connector disabled list scoped to the new company id — CEO
  model validation runs against the company's freshly-persisted pool,
  not some stale global.
- IPC setConnectorDisabledModels now requires companyId; the only
  consumer was onboarding, which no longer calls it at all.
- Main-side listConnectorModels returns the raw provider catalog
  (no pool filtering), since that IPC is used from onboarding where
  no company exists yet; pool filtering happens at dispatch time.

saveConnector IPC drops the per-company pool validation — connector
config is a global hint, company-scoped enforcement belongs at run
dispatch where the company is known.

Tests: 603/603 green. Typecheck clean. Integration tests rewritten
to set the pool via connectorPoolSelections on bootstrap input, not
a pre-bootstrap global setDisabledModels call.

src/main/database/migrations/v42-v42.ts

@@ -0,0 +1,64 @@
+import log from "electron-log/main.js";
+import type { Migration, MigrationDeps } from "./types";
+import { tableExists } from "./types";
+
+/**
+ * Company-scope the connector model-pool settings.
+ *
+ * "Model pool" is the per-connector list of models a user has
+ * enabled/disabled during onboarding (Settings → Model pool). The
+ * original storage put it in the key-value `settings` table under
+ * `disabled_models:${connectorId}` — global, not tied to any
+ * company. That meant deleting a company left the pool config behind,
+ * and creating a new company inherited the previous company's
+ * enabled/disabled choices.
+ *
+ * This migration moves the data to a real relational table with a
+ * cascade FK. Company deletion now naturally wipes the settings —
+ * no manual cleanup in `deleteCompany()`, no risk of drift.
+ *
+ * Existing global entries cannot be assigned to a single company
+ * (the constraint they were written under had none), so the
+ * migration drops them. Users re-select their model pool on the
+ * next onboarding wake. Acceptable: this data is a one-click UI
+ * preference, not business-critical state, and the bug report was
+ * literally "these carry over wrongly — clear them."
+ */
+export function createMigrationsV42V42(deps: MigrationDeps): Migration[] {
+  const { db } = deps;
+  return [
+    {
+      version: 42,
+      name: "scope_connector_model_pool_by_company",
+      fn: () => {
+        if (!tableExists(db, "connector_model_pool_settings")) {
+          db.exec(`
+            CREATE TABLE connector_model_pool_settings (
+              company_id TEXT NOT NULL,
+              connector_id TEXT NOT NULL,
+              disabled_models_json TEXT NOT NULL DEFAULT '[]',
+              updated_at TEXT NOT NULL,
+              PRIMARY KEY (company_id, connector_id),
+              FOREIGN KEY (company_id) REFERENCES companies(id) ON DELETE CASCADE
+            );
+            CREATE INDEX IF NOT EXISTS idx_connector_model_pool_company
+              ON connector_model_pool_settings(company_id);
+          `);
+          log.info("[migration v42] created connector_model_pool_settings");
+        }
+
+        // Purge stale global keys. Prefix scan is enough — both the
+        // key format (`disabled_models:<connectorId>`) and the
+        // semantics (one per connector) mean dropping them all is the
+        // correct reset.
+        const deleted = db
+          .prepare("DELETE FROM settings WHERE key LIKE 'disabled_models:%'")
+          .run();
+        const changes = Number(deleted.changes);
+        if (changes > 0) {
+          log.info(`[migration v42] dropped ${changes} legacy disabled_models:* key(s) from settings`);
+        }
+      },
+    },
+  ];
+}