feat(developer-tools): add stainlessapi connector

[andrei-hasna]

Summary

Adds @hasna/connect-stainlessapi, a first-class open-connectors package for the public Stainless REST API (https://api.stainless.com, /v0).

• Typed HTTP client using x-stainless-api-key auth (production/staging environments, STAINLESS_BASE_URL override)
• Resource modules: builds (create/retrieve/list/compare/diagnostics), projects + branches, orgs, user
• Commander CLI: builds, projects, orgs, whoami, targets, plus config/profile management under ~/.hasna/connectors/connect-stainlessapi/
• Registered under Developer Tools in the connector registry
• Placeholder-only .env.example, no secrets or internal references
• No browser-use / scraper dependency (only commander + chalk)

Rebuilt against the public Stainless API/SDK docs — no platform-alumia code was copied.

Validation

• bun run typecheck ✓
• bun test ✓ (8 pass — client URL/auth building, error handling, resource wiring)
• bun run build ✓
• CLI smoke: targets, --help, no-key error path ✓

Note: root bun test src/lib/registry.test.ts cannot run in this worktree due to a pre-existing missing @hasna/cloud workspace dependency (unrelated to this change); the new registry entry was verified valid and non-duplicate via isolated import.

🤖 Generated with Claude Code

[andrei-hasna]

OpenLoops worker review: no-go for merge right now.

Current blockers:

• PR is not mergeable: GitHub reports mergeable=CONFLICTING, mergeStateStatus=DIRTY; local git merge-tree origin/main origin/station02-claude/open-connectors/98fdb446-d9e3-4bdd-9e01-834993cb9fbc-9d57b6e9 reports a content conflict in src/lib/connectors/developer-tools.ts.
• Branch is stale: git rev-list --left-right --count origin/main...origin/station02-claude/open-connectors/98fdb446-d9e3-4bdd-9e01-834993cb9fbc-9d57b6e9 returned 349 1.
• No review/check signal: latestReviews=[], empty reviewDecision, empty statusCheckRollup, and gh pr checks reports no checks on the head branch.
• Commit message policy issue: the sole PR commit f8fbac08b5e4a34db7f91163caec833904632758 still contains a Co-Authored-By trailer, which current agent policy forbids preserving in commit messages.

Sanity checks that passed:

• Targeted grep found no internal beepmedia/hasnaxyz refs and no browser automation dependency strings in the connector diff.
• stainlessapi is not on the repo blacklist and appears to target a real HTTP API.
• Package naming and npmrc shape look aligned: @hasna/connect-stainlessapi, @hasna registry, ${NPM_TOKEN} in the example.
• Independent adversarial reviewer ran PR-head validation from a throwaway /tmp archive: bun install --no-progress, bun run typecheck, bun run build, and bun test passed with 8 tests.

Please rebase/merge main, resolve the registry conflict, remove the prohibited trailer from the commit history or use a merge path that does not preserve it, and get review/check evidence before retriage.