fix(#1392 followup): review-285 N1+N2 — env has no config authority in schema-check; verification throws are fatal at install

N1: resolveSchemaCheckConfigPath drops the MOSAIC_CONFIG env candidate entirely
(mirrors apps/gateway/src/env.ts's deliberate env-has-no-config-authority
stance; a stale env var could verify a database the daemon never reads).
verify.ts now passes undefined rather than the env var. New spec: a decoy
MOSAIC_CONFIG must never win over the daemon-written config.

N2: install treats a THROWN post-install verification as fatal (exit 1 with
remediation pointer) in addition to the existing result-object hard-fail —
an install must never report success over an unverified database, whichever
way the check failed.

packages/mosaic/src/commands/gateway/install.ts

@@ -95,11 +95,17 @@ export async function runInstall(opts: InstallOpts): Promise<void> {
     // fatal (#1392): an install that reports success over an empty/partial
     // database is the exact T63 failure this command must never reproduce.
     let verifyResult: VerifyResult | undefined;
+    let verificationThrew = false;
     try {
       const { runPostInstallVerification } = await import('./verify.js');
       verifyResult = await runPostInstallVerification(configResult.host, configResult.port);
-    } catch {
+    } catch (err) {
-      // Non-fatal — verification is a courtesy
+      // Health/token/bootstrap courtesy failures are non-fatal, but a THROWN
+      // schema verification must not let install report success either (N2,
+      // rev-code-02 review 285): mark it and treat as fatal below.
+      verificationThrew = true;
+      const msg = err instanceof Error ? err.message : String(err);
+      prompter.warn(`Post-install verification errored: ${msg}`);
     }
     if (verifyResult && verifyResult.schemaMigrated === false) {
       prompter.warn(
@@ -107,6 +113,12 @@ export async function runInstall(opts: InstallOpts): Promise<void> {
       );
       process.exit(1);
     }
+    if (verificationThrew) {
+      prompter.warn(
+        'Gateway install ABORTED: post-install verification errored (see above); refusing to report success on an unverified database.',
+      );
+      process.exit(1);
+    }
   } catch (err) {
     // Stages normally return structured results for expected failures.
     // Anything that reaches here is an unexpected runtime error — render a

packages/mosaic/src/commands/gateway/schema-check.spec.ts

@@ -153,4 +153,29 @@ describe('resolveSchemaCheckConfigPath', () => {
       if (prevHome !== undefined) vi.stubEnv('HOME', prevHome);
     }
   });
+
+  it('gives MOSAIC_CONFIG NO authority (N1, review 285): env never overrides file resolution', async () => {
+    const { resolveSchemaCheckConfigPath } = await import('./schema-check.js');
+    const daemonDir = mkdtempSync(join(tmpdir(), 'schema-check-env-'));
+    tmpDirs.push(daemonDir);
+    const daemonHome = join(daemonDir, '.config', 'mosaic', 'gateway');
+    mkdirSync(daemonHome, { recursive: true });
+    writeFileSync(join(daemonHome, 'mosaic.config.json'), JSON.stringify(LOCAL_CFG));
+    // A stale env var pointing at a DIFFERENT file must be ignored entirely:
+    const decoyDir = mkdtempSync(join(tmpdir(), 'schema-check-decoy-'));
+    tmpDirs.push(decoyDir);
+    const decoyPath = join(decoyDir, 'mosaic.config.json');
+    writeFileSync(decoyPath, JSON.stringify(STANDALONE_CFG));
+
+    const prevHome = process.env['HOME'];
+    vi.stubEnv('HOME', daemonDir);
+    vi.stubEnv('MOSAIC_CONFIG', decoyPath);
+    try {
+      const resolved = resolveSchemaCheckConfigPath();
+      expect(resolved).toBe(join(daemonHome, 'mosaic.config.json'));
+      expect(resolved).not.toBe(decoyPath);
+    } finally {
+      if (prevHome !== undefined) vi.stubEnv('HOME', prevHome);
+    }
+  });
 });

packages/mosaic/src/commands/gateway/schema-check.ts

@@ -53,8 +53,11 @@ export const SCHEMA_FAIL_REMEDIATION = [
  */
 export function resolveSchemaCheckConfigPath(explicit?: string): string | undefined {
   if (explicit) return resolve(explicit);
+  // NOTE: no env-var candidate, deliberately. apps/gateway/src/env.ts gives env
+  // NO config authority (a stale MOSAIC_CONFIG could verify a database the
+  // daemon never reads — rev-code-02 review 285, note N1). Resolution order
+  // mirrors the daemon's file priorities only.
   const candidates = [
-    process.env['MOSAIC_CONFIG'],
     join(homedir(), '.config', 'mosaic', 'gateway', 'mosaic.config.json'), // daemon-written
     resolve(process.cwd(), 'mosaic.config.json'),
     join(homedir(), '.mosaic', 'mosaic.config.json'),

packages/mosaic/src/commands/gateway/verify.ts

@@ -101,7 +101,7 @@ export async function runPostInstallVerification(
     const { runMigrations, getMigrationStatus } = await import('@mosaicstack/db');
     const result = await checkDatabaseSchema(
       { runMigrations, getMigrationStatus },
-      process.env['MOSAIC_CONFIG'],
+      undefined, // resolver mirrors daemon file priorities; env has no config authority (N1)
     );
     if (result.status === 'ok') {
       ok(result.detail);