Add connected account handle/provider index (#23580)

## Context

Google messaging webhook notifications resolve connected accounts with
an equality lookup on both `handle` and `provider`:

```ts
connectedAccountRepository.find({
  where: {
    handle: decodedData.emailAddress,
    provider: ConnectedAccountProvider.GOOGLE,
  },
});
```

This lookup runs for incoming Gmail notifications, but
`connectedAccount` currently has no index matching either predicate. As
the table grows, PostgreSQL has to inspect unrelated connected-account
rows for each notification. Under sustained webhook traffic, that adds
avoidable database work and keeps database connections occupied longer.

## What changed

- Add a composite B-tree index on `connectedAccount(handle, provider)`.
- Register the index in the TypeORM entity metadata.
- Add an idempotent 2.26 fast instance command to create the index for
existing installations and remove it on rollback.

The webhook handler and query behavior remain unchanged.

## Why this index

- Both query predicates are equality conditions, so the composite index
supports a targeted lookup.
- `handle` is first because it is the more selective value and also
makes the index useful for handle-prefixed lookups.
- The index is intentionally non-unique. The same provider handle may
legitimately belong to connected accounts in different workspaces, and
this change must not introduce a new data constraint.
- Connected accounts are read by webhooks much more frequently than
their handle or provider changes, so index maintenance overhead should
remain small.

## Expected impact

Webhook account resolution should use an index lookup instead of
scanning the connected-account table. This reduces cumulative PostgreSQL
work and connection occupancy on the Gmail notification path.

This is a targeted database optimization. It should reduce pressure
generated by this high-frequency query, but it is not expected to
resolve every source of API tail latency by itself.

## Safety and rollout

- The instance command uses `CREATE INDEX IF NOT EXISTS` and `DROP INDEX
IF EXISTS`.
- No uniqueness or application behavior changes are introduced.
- Existing rows require no data backfill.
- The index adds bounded storage and write-maintenance overhead.

## Validation

- `yarn nx typecheck twenty-server`
- Type-aware Oxlint on the changed files
- Oxfmt on the changed files
- `git diff --check`


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packages/twenty-server/src/database/commands/upgrade-version-command/2-26/2-26-instance-command-fast-1785420705255-add-connected-account-handle-provider-index.ts

@@ -0,0 +1,19 @@
+import { type QueryRunner } from 'typeorm';
+
+import { RegisteredInstanceCommand } from 'src/engine/core-modules/upgrade/decorators/registered-instance-command.decorator';
+import { type FastInstanceCommand } from 'src/engine/core-modules/upgrade/interfaces/fast-instance-command.interface';
+
+@RegisteredInstanceCommand('2.26.0', 1785420705255)
+export class AddConnectedAccountHandleProviderIndexFastInstanceCommand implements FastInstanceCommand {
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      'CREATE INDEX IF NOT EXISTS "IDX_CONNECTED_ACCOUNT_HANDLE_PROVIDER" ON "core"."connectedAccount" ("handle", "provider")',
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      'DROP INDEX IF EXISTS "core"."IDX_CONNECTED_ACCOUNT_HANDLE_PROVIDER"',
+    );
+  }
+}

packages/twenty-server/src/database/commands/upgrade-version-command/instance-commands.constant.ts

@@ -130,6 +130,7 @@ import { AddAppTokenSsoExchangeIndexFastInstanceCommand } from './2-25/2-25-inst
 import { AddPageLayoutCascadeDeleteIndexesFastInstanceCommand } from './2-25/2-25-instance-command-fast-1784904030251-add-page-layout-cascade-delete-indexes';
 import { AddChannelWebhookSubscriptionExternalIdIndexesFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-25/2-25-instance-command-fast-1785173910915-add-channel-webhook-subscription-external-id-indexes';
 import { AddIsHiddenToAgentMessageFastInstanceCommand } from './2-25/2-25-instance-command-fast-1785230296000-add-is-hidden-to-agent-message';
+import { AddConnectedAccountHandleProviderIndexFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-26/2-26-instance-command-fast-1785420705255-add-connected-account-handle-provider-index';
 
 export const INSTANCE_COMMANDS = [
   AddViewFieldGroupIdIndexOnViewFieldFastInstanceCommand,
@@ -262,4 +263,5 @@ export const INSTANCE_COMMANDS = [
   AddPageLayoutCascadeDeleteIndexesFastInstanceCommand,
   AddChannelWebhookSubscriptionExternalIdIndexesFastInstanceCommand,
   AddIsHiddenToAgentMessageFastInstanceCommand,
+  AddConnectedAccountHandleProviderIndexFastInstanceCommand,
 ];

packages/twenty-server/src/engine/metadata-modules/connected-account/entities/connected-account.entity.ts

@@ -27,6 +27,7 @@ export type ConnectedAccountVisibility = 'user' | 'workspace';
 @Entity({ name: 'connectedAccount', schema: 'core' })
 @Index('IDX_CONNECTED_ACCOUNT_CONNECTION_PROVIDER_ID', ['connectionProviderId'])
 @Index('IDX_CONNECTED_ACCOUNT_APPLICATION_ID', ['applicationId'])
+@Index('IDX_CONNECTED_ACCOUNT_HANDLE_PROVIDER', ['handle', 'provider'])
 @Check(
   'CHK_connectedAccount_accessToken_encrypted',
   `"accessToken" IS NULL OR "accessToken" LIKE 'enc:v2:%'`,