Add MCP authorization HTTP flow (#32)

## Summary

- add service-authenticated issuance of short-lived signed MCP
authorization tickets
- make client identity, client label and requested scope tamper-evident
before the human consent step
- add human session endpoints to inspect a request, authorize one
manageable agent, list grants and revoke access
- add single-use delegation redemption and active-grant resolution for
the MCP Worker
- revalidate active account status and current sponsor/platform-owner
authority on every redemption and use
- classify MCP service traffic separately in telemetry

## Security boundary

- the browser submits only a signed ticket and selected agent ID
- v0.2A remains fixed to `feed:read`
- no `orb_agent_v1` credential is accepted, copied or stored
- authorization tickets expire after 10 minutes
- delegation codes expire after 5 minutes and can be redeemed once
- grants expire after 90 days and are immediately revocable

## Verification

- `npm run check` — 0 diagnostics
- `npm run test:d1` — 122/122 passed
- `npm run build` — full D1, content, client, site and browser
regression passed

Author: sametbasbug

migrations/0023_mcp_authorization_source_truth.sql

@@ -0,0 +1,42 @@
+PRAGMA foreign_keys = ON;
+
+DROP TRIGGER IF EXISTS mcp_delegation_redemptions_validate;
+
+CREATE TRIGGER mcp_delegation_redemptions_validate
+BEFORE INSERT ON mcp_delegation_redemptions
+BEGIN
+  SELECT RAISE(ABORT, 'invalid_mcp_delegation_code')
+  WHERE NOT EXISTS (
+    SELECT 1
+    FROM mcp_delegation_codes code
+    JOIN mcp_authorization_grants grant_row
+      ON grant_row.id = code.grant_id
+    JOIN accounts account
+      ON account.id = grant_row.account_id
+    WHERE code.id = NEW.code_id
+      AND code.grant_id = NEW.grant_id
+      AND code.authorization_request_id = NEW.authorization_request_id
+      AND code.consumed_at IS NULL
+      AND code.expires_at > NEW.redeemed_at
+      AND grant_row.revoked_at IS NULL
+      AND (grant_row.expires_at IS NULL OR grant_row.expires_at > NEW.redeemed_at)
+      AND account.status = 'active'
+      AND (
+        EXISTS (
+          SELECT 1
+          FROM agent_memberships membership
+          WHERE membership.agent_id = grant_row.agent_id
+            AND membership.account_id = grant_row.account_id
+            AND membership.role = 'primary_sponsor'
+            AND membership.revoked_at IS NULL
+        )
+        OR EXISTS (
+          SELECT 1
+          FROM account_roles role
+          WHERE role.account_id = grant_row.account_id
+            AND role.role = 'platform_owner'
+            AND role.revoked_at IS NULL
+        )
+      )
+  );
+END;

scripts/orbit-d1-test-worker.ts

@@ -346,6 +346,22 @@ async function handleAction(body: ActionRequest, env: Environment): Promise<Resp
       return json({ redemption, revocation, audits: audits.results });
     }
 
+    case 'revokeMcpMembership': {
+      await env.DB.prepare(`
+        UPDATE agent_memberships
+        SET revoked_at = ?
+        WHERE account_id = ?
+          AND agent_id = ?
+          AND role = 'primary_sponsor'
+          AND revoked_at IS NULL
+      `).bind(
+        numberValue(data, 'now'),
+        stringValue(data, 'accountId'),
+        stringValue(data, 'agentId'),
+      ).run();
+      return json({ ok: true });
+    }
+
     case 'exportBackup': {
       return json(await createDynamicBackup(
         env.DB,

scripts/orbit-mcp-authorization-tests.ts

@@ -401,6 +401,36 @@ describe('Orbit MCP authorization foundation', { concurrency: false }, () => {
     );
   });
 
+  test('losing current agent management invalidates touch and redemption', async () => {
+    const now = Date.now();
+    const accountId = 'mcp-source-truth-sponsor';
+    const agentId = 'mcp-source-truth-agent';
+    await callAction('seedMcpAgent', { accountId, agentId, now });
+    const input = grantData('mcp-source-truth', accountId, agentId, now + 1);
+    await callAction('createMcpGrant', input, 201);
+    await callAction('revokeMcpMembership', {
+      accountId,
+      agentId,
+      now: now + 2,
+    });
+
+    const touched = await callAction<{ touched: boolean }>(
+      'touchMcpGrant',
+      { grantId: input.grantId, now: now + 3 },
+    );
+    assert.equal(touched.touched, false);
+
+    const redemption = await callAction<{ error: string }>('redeemMcpCode', {
+      codeId: input.codeId,
+      grantId: input.grantId,
+      authorizationRequestId: input.authorizationRequestId,
+      auditEventId: 'mcp-source-truth-redeem-audit',
+      requestId: 'mcp-source-truth-redeem-request',
+      now: now + 4,
+    }, 409);
+    assert.match(redemption.error, /invalid_mcp_delegation_code/u);
+  });
+
   test('durable grants and revocations enter backups without transient codes', async () => {
     const backup = await callAction<{
       schemaVersion: number;