refactor(e2e): extract infrastructure into tests/e2e/infra/ module

- Move fixtures.ts, llm-judge.ts, results-db.ts to tests/e2e/infra/
- Deduplicate wdio.conf.js: use createTestFixture() instead of inline copy
- Replace __dirname paths with projectRoot-anchored paths
- Create test-mode-constants.ts (typed env var names, flag registry)
- Create scripts/preflight-check.sh (validates tauri-driver, display, Claude CLI)
- Create scripts/check-test-flags.sh (CI lint for AGOR_TEST flag drift)
- Rewrite tests/e2e/README.md with full documentation
- Update spec imports for moved infra files

tests/e2e/infra/fixtures.ts

@@ -0,0 +1,142 @@
+// Test fixture generator — creates isolated test environments
+// Used by E2E tests to set up temp data/config dirs with valid groups.json
+
+import { mkdirSync, writeFileSync, rmSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
+import { execSync } from 'node:child_process';
+import { tmpdir } from 'node:os';
+
+export interface TestFixture {
+  /** Root temp directory for this test run */
+  rootDir: string;
+  /** AGOR_TEST_DATA_DIR — isolated data dir */
+  dataDir: string;
+  /** AGOR_TEST_CONFIG_DIR — isolated config dir */
+  configDir: string;
+  /** Path to a minimal git repo for agent testing */
+  projectDir: string;
+  /** Environment variables to pass to the app */
+  env: Record<string, string>;
+}
+
+/**
+ * Create an isolated test fixture with:
+ * - Temp data dir (sessions.db, btmsg.db created at runtime)
+ * - Temp config dir with a minimal groups.json
+ * - A simple git repo with one file for agent testing
+ */
+export function createTestFixture(name = 'agor-e2e'): TestFixture {
+  const rootDir = join(tmpdir(), `${name}-${Date.now()}`);
+  const dataDir = join(rootDir, 'data');
+  const configDir = join(rootDir, 'config');
+  const projectDir = join(rootDir, 'test-project');
+
+  // Create directory structure
+  mkdirSync(dataDir, { recursive: true });
+  mkdirSync(configDir, { recursive: true });
+  mkdirSync(projectDir, { recursive: true });
+
+  // Create a minimal git repo for agent testing
+  execSync('git init', { cwd: projectDir, stdio: 'ignore' });
+  execSync('git config user.email "test@agor.dev"', { cwd: projectDir, stdio: 'ignore' });
+  execSync('git config user.name "Agor Test"', { cwd: projectDir, stdio: 'ignore' });
+  writeFileSync(join(projectDir, 'README.md'), '# Test Project\n\nA simple test project for Agor E2E tests.\n');
+  writeFileSync(join(projectDir, 'hello.py'), 'def greet(name: str) -> str:\n    return f"Hello, {name}!"\n');
+  execSync('git add -A && git commit -m "initial commit"', { cwd: projectDir, stdio: 'ignore' });
+
+  // Write groups.json with one group containing the test project
+  const groupsJson = {
+    version: 1,
+    groups: [
+      {
+        id: 'test-group',
+        name: 'Test Group',
+        projects: [
+          {
+            id: 'test-project',
+            name: 'Test Project',
+            identifier: 'test-project',
+            description: 'E2E test project',
+            icon: '\uf120',
+            cwd: projectDir,
+            profile: 'default',
+            enabled: true,
+          },
+        ],
+        agents: [],
+      },
+    ],
+    activeGroupId: 'test-group',
+  };
+
+  writeFileSync(
+    join(configDir, 'groups.json'),
+    JSON.stringify(groupsJson, null, 2),
+  );
+
+  const env: Record<string, string> = {
+    AGOR_TEST: '1',
+    AGOR_TEST_DATA_DIR: dataDir,
+    AGOR_TEST_CONFIG_DIR: configDir,
+  };
+
+  return { rootDir, dataDir, configDir, projectDir, env };
+}
+
+/**
+ * Clean up a test fixture's temporary directories.
+ */
+export function destroyTestFixture(fixture: TestFixture): void {
+  if (existsSync(fixture.rootDir)) {
+    rmSync(fixture.rootDir, { recursive: true, force: true });
+  }
+}
+
+/**
+ * Create a groups.json with multiple projects for multi-project testing.
+ */
+export function createMultiProjectFixture(projectCount = 3): TestFixture {
+  const fixture = createTestFixture('agor-multi');
+
+  const projects = [];
+  for (let i = 0; i < projectCount; i++) {
+    const projDir = join(fixture.rootDir, `project-${i}`);
+    mkdirSync(projDir, { recursive: true });
+    execSync('git init', { cwd: projDir, stdio: 'ignore' });
+    execSync('git config user.email "test@agor.dev"', { cwd: projDir, stdio: 'ignore' });
+    execSync('git config user.name "Agor Test"', { cwd: projDir, stdio: 'ignore' });
+    writeFileSync(join(projDir, 'README.md'), `# Project ${i}\n`);
+    execSync('git add -A && git commit -m "init"', { cwd: projDir, stdio: 'ignore' });
+
+    projects.push({
+      id: `project-${i}`,
+      name: `Project ${i}`,
+      identifier: `project-${i}`,
+      description: `Test project ${i}`,
+      icon: '\uf120',
+      cwd: projDir,
+      profile: 'default',
+      enabled: true,
+    });
+  }
+
+  const groupsJson = {
+    version: 1,
+    groups: [
+      {
+        id: 'multi-group',
+        name: 'Multi Project Group',
+        projects,
+        agents: [],
+      },
+    ],
+    activeGroupId: 'multi-group',
+  };
+
+  writeFileSync(
+    join(fixture.configDir, 'groups.json'),
+    JSON.stringify(groupsJson, null, 2),
+  );
+
+  return fixture;
+}