feat(docs): add Sentry SDK for error tracking, replay, and metrics

[betegon]

Summary

Adds @sentry/astro to the docs website for monitoring errors, user sessions, and performance. Also tracks custom metrics when users interact with the hero install command section.

Changes

• Integrates @sentry/astro with client and server configs
• Enables error tracking, session replay (10% sample, 100% on error), and tracing
• Adds two custom metrics:
  • hero_command_copied - tracks when users copy an install command
  • hero_install_method_selected - tracks when users switch between curl/npx/npm/pnpm/bun

Test Plan

1. Run cd docs && bun run dev
2. Open browser console and verify Sentry initializes (enable debug: true in client config if needed)
3. Click the dropdown to change install method → metric sent
4. Click copy button → metric sent
5. Check Sentry project Insights > Metrics for the custom metrics

Notes

• SENTRY_AUTH_TOKEN env var needed for source maps upload in production
• SDK is enabled in all environments including dev for testing

---

Closes #117

[github-actions]

Semver Impact of This PR

🟡 Minor (new features)

📋 Changelog Preview

This is how your changes will appear in the changelog.
Entries from this PR are highlighted with a left border (blockquote style).

---

New Features ✨

• (docs) Add Sentry SDK for error tracking, replay, and metrics by betegon in #122

---

_{🤖 This preview updates automatically when you update the PR.}

[github-actions]

Codecov Results 📊

✅ Patch coverage is 100.00%. Project has 1756 uncovered lines.
✅ Project coverage is 66.66%. Comparing base (base) to head (head).

Files with missing lines (24)

File	Patch %	Lines
human.ts	30.83%	⚠️ 673 Missing
resolve-target.ts	18.93%	⚠️ 257 Missing
oauth.ts	21.71%	⚠️ 202 Missing
resolver.ts	3.23%	⚠️ 120 Missing
errors.ts	5.94%	⚠️ 95 Missing
api-client.ts	68.77%	⚠️ 94 Missing
migration.ts	47.44%	⚠️ 82 Missing
api.ts	89.80%	⚠️ 47 Missing
seer.ts	75.54%	⚠️ 45 Missing
errors.ts	73.17%	⚠️ 33 Missing
seer.ts	76.15%	⚠️ 31 Missing
preload.ts	39.02%	⚠️ 25 Missing
detector.ts	87.79%	⚠️ 16 Missing
telemetry.ts	89.87%	⚠️ 8 Missing
auth.ts	93.69%	⚠️ 7 Missing
index.ts	95.06%	⚠️ 4 Missing
colors.ts	91.84%	⚠️ 4 Missing
env-file.ts	97.17%	⚠️ 3 Missing
utils.ts	98.64%	⚠️ 2 Missing
alias.ts	98.56%	⚠️ 2 Missing
project-aliases.ts	97.40%	⚠️ 2 Missing
schema.ts	90.00%	⚠️ 2 Missing
java.ts	97.22%	⚠️ 1 Missing
parser.ts	98.63%	⚠️ 1 Missing

Coverage diff

@@            Coverage Diff             @@
##          main       #PR       +/-##
==========================================
+ Coverage    66.66%    66.66%        —%
==========================================
  Files           45        45         —
  Lines         5267      5267         —
  Branches         0         0         —
==========================================
+ Hits          3511      3511         —
- Misses        1756      1756         —
- Partials         0         0         —

---

Generated by Codecov Action

[github-actions]

PR Preview Action v1.8.1
🚀 View preview at https://cli.sentry.dev/pr-preview/pr-122/
Built to branch gh-pages at 2026-01-30 10:12 UTC. Preview will be ready when the GitHub Pages deployment is complete.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}