Scaffold dd0c/portal: AWS+GitHub discovery, catalog service, ownership resolution

- AWS scanner: ECS/Lambda/RDS discovery with partial failure handling
- GitHub scanner: CODEOWNERS parsing, commit-based heuristic ownership, rate limit resilience
- Catalog service: ownership resolution (config > codeowners > aws-tag > heuristic), staged updates for partial scans
- Ownership tests: 6 cases covering full priority chain
- PostgreSQL schema with RLS: services, staged_updates, scan_history, free tier (50 services)
- Fly.io config, Dockerfile

products/04-lightweight-idp/src/discovery/github-scanner.ts

@@ -0,0 +1,139 @@
+import pino from 'pino';
+import type { DiscoveredService } from './aws-scanner.js';
+
+const logger = pino({ name: 'discovery-github' });
+
+export interface GitHubScanResult {
+  status: 'success' | 'partial_failure' | 'failed';
+  discovered: number;
+  errors: string[];
+  repos: GitHubRepo[];
+}
+
+export interface GitHubRepo {
+  name: string;
+  fullName: string;
+  owner: string;
+  ownerSource: 'codeowners' | 'heuristic';
+  language: string;
+  defaultBranch: string;
+  topics: string[];
+  lastPush: Date;
+  codeownersContent?: string;
+}
+
+/**
+ * GitHub Discovery Scanner.
+ * Reads repos, CODEOWNERS, and infers ownership from commit history.
+ * Partial failures (rate limits) preserve existing catalog entries.
+ */
+export class GitHubDiscoveryScanner {
+  private octokit: any;
+
+  constructor(octokit: any) {
+    this.octokit = octokit;
+  }
+
+  async scan(org: string): Promise<GitHubScanResult> {
+    const repos: GitHubRepo[] = [];
+    const errors: string[] = [];
+
+    try {
+      const { data } = await this.octokit.repos.listForOrg({
+        org,
+        per_page: 100,
+        sort: 'pushed',
+      });
+
+      for (const repo of data) {
+        try {
+          const owner = await this.resolveOwner(org, repo.name, repo.default_branch);
+          repos.push({
+            name: repo.name,
+            fullName: repo.full_name,
+            owner: owner.owner,
+            ownerSource: owner.source,
+            language: repo.language ?? 'unknown',
+            defaultBranch: repo.default_branch,
+            topics: repo.topics ?? [],
+            lastPush: new Date(repo.pushed_at),
+          });
+        } catch (err) {
+          errors.push(`Repo ${repo.name}: ${(err as Error).message}`);
+        }
+      }
+    } catch (err) {
+      const msg = (err as Error).message;
+      if (msg.includes('rate limit')) {
+        logger.warn({ org }, 'GitHub rate limited during scan');
+        return { status: 'partial_failure', discovered: repos.length, errors: [msg], repos };
+      }
+      return { status: 'failed', discovered: 0, errors: [msg], repos: [] };
+    }
+
+    return {
+      status: errors.length > 0 ? 'partial_failure' : 'success',
+      discovered: repos.length,
+      errors,
+      repos,
+    };
+  }
+
+  private async resolveOwner(org: string, repo: string, branch: string): Promise<{ owner: string; source: 'codeowners' | 'heuristic' }> {
+    // Try CODEOWNERS first (explicit > heuristic)
+    try {
+      const { data } = await this.octokit.repos.getContent({
+        owner: org,
+        repo,
+        path: '.github/CODEOWNERS',
+        ref: branch,
+      });
+      const content = Buffer.from(data.content, 'base64').toString();
+      const owner = parseCodeowners(content);
+      if (owner) return { owner, source: 'codeowners' };
+    } catch {
+      // No CODEOWNERS file — fall through to heuristic
+    }
+
+    // Heuristic: top committer in last 90 days
+    try {
+      const { data } = await this.octokit.repos.listCommits({
+        owner: org,
+        repo,
+        per_page: 50,
+        since: new Date(Date.now() - 90 * 24 * 60 * 60 * 1000).toISOString(),
+      });
+      const authors = data
+        .map((c: any) => c.author?.login)
+        .filter(Boolean);
+      const topAuthor = mode(authors);
+      if (topAuthor) return { owner: topAuthor, source: 'heuristic' };
+    } catch {
+      // Can't determine owner
+    }
+
+    return { owner: 'unknown', source: 'heuristic' };
+  }
+}
+
+function parseCodeowners(content: string): string | null {
+  const lines = content.split('\n').filter(l => l.trim() && !l.startsWith('#'));
+  // Last matching rule wins in CODEOWNERS — take the global rule (* @team)
+  const globalRule = lines.find(l => l.startsWith('*'));
+  if (globalRule) {
+    const parts = globalRule.split(/\s+/);
+    return parts[1]?.replace('@', '') ?? null;
+  }
+  return lines[0]?.split(/\s+/)[1]?.replace('@', '') ?? null;
+}
+
+function mode(arr: string[]): string | null {
+  const freq: Record<string, number> = {};
+  for (const item of arr) freq[item] = (freq[item] ?? 0) + 1;
+  let max = 0;
+  let result: string | null = null;
+  for (const [key, count] of Object.entries(freq)) {
+    if (count > max) { max = count; result = key; }
+  }
+  return result;
+}