test(examples): give each run its own sqlite database

The test profile pointed at ./test.db in the app directory, so a run inherited
whatever schema an earlier run left behind. On a machine with a stale file,
0003_add_password re-applied ALTER TABLE ADD COLUMN over a column that already
existed; fail-on-test-warnings turned the warning into a failure, and
check:production failed for environment reasons rather than code.

Each run now uses a fresh database under the OS temp directory. Verified by
restoring the stale dev.db and test.db that reproduced the failure: the suite
passes with them present.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

examples/basic-app/wrnexus.config.ts

@@ -1,3 +1,6 @@
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
 import type { AppConfig } from "@wrnexus/styles";
 
 /**
@@ -100,7 +103,14 @@ const config: AppConfig = {
       seo: { title: "WrNexus (UAT)", robots: "noindex,nofollow" },
     },
     test: {
-      db: { driver: "sqlite", url: "file:./test.db" },
+      // A fresh database per run. A file checked into the working tree would
+      // carry a schema from an earlier run, and a migration such as
+      // 0003_add_password then re-applies against a column that already
+      // exists, failing the suite on developer machines but not on CI.
+      db: {
+        driver: "sqlite",
+        url: `file:${join(tmpdir(), `wrnexus-test-${process.pid}.db`)}`,
+      },
     },
   },
 };

examples/inter-app-api-showcase/apps/admin/wrnexus.config.ts

@@ -1,3 +1,6 @@
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
 import type { AppConfig } from "@wrnexus/styles";
 
 const config: AppConfig = {
@@ -133,7 +136,11 @@ const config: AppConfig = {
   profiles: {
     development: {},
     test: {
-      db: { driver: "sqlite", url: "file:./test.db" },
+      // A fresh database per run; a persisted file carries an earlier schema.
+      db: {
+        driver: "sqlite",
+        url: `file:${join(tmpdir(), `wrnexus-test-${process.pid}.db`)}`,
+      },
       observability: { exporter: "none", sampleRate: 0 },
     },
     staging: {

examples/inter-app-api-showcase/apps/web/wrnexus.config.ts

@@ -1,3 +1,6 @@
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
 import type { AppConfig } from "@wrnexus/styles";
 
 const config: AppConfig = {
@@ -133,7 +136,11 @@ const config: AppConfig = {
   profiles: {
     development: {},
     test: {
-      db: { driver: "sqlite", url: "file:./test.db" },
+      // A fresh database per run; a persisted file carries an earlier schema.
+      db: {
+        driver: "sqlite",
+        url: `file:${join(tmpdir(), `wrnexus-test-${process.pid}.db`)}`,
+      },
       observability: { exporter: "none", sampleRate: 0 },
     },
     staging: {