chore: add Biome, Husky, commitlint, and GitHub Actions CI

[bassochette]

Summary

• Biome v2 for linting and formatting — single quotes, semicolons, 2-space indent, 100 line width, LF endings
• Husky + lint-staged pre-commit hook auto-fixes staged .ts/.js files with Biome
• Commitlint enforces conventional commit messages via commit-msg hook
• GitHub Actions CI with 3 jobs: lint & format check, test with 80% coverage threshold + PR comments, build verification
• Auto-fixed all 24 source files to pass Biome checks (node: protocol imports, template literals, unused params, formatting)

Test plan

• bun run check passes with no errors
• Pre-commit hook runs lint-staged successfully on commit
• Commit-msg hook validates conventional commit format
• CI pipeline runs all 3 jobs on PR

🤖 Generated with Claude Code

[github-actions]

Coverage after merging contributing-guidelines into main will be

47.96%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
config.ts	100%	100%	100%	100%
index.ts	79.71%	100%	85.71%	79.39%	13–20, 209, 21, 211–213, 22–23, 232–236, 238–240, 243–245, 257
orchestrator.ts	27.38%	100%	36.36%	27.07%	131–132, 134–138, 142–149, 154–160, 163–164, 166, 168–169, 171–174, 176–180, 182–189, 215–216, 223–232, 249, 253, 255–256, 258–262, 264–265, 268–271, 274–283, 285, 287–295, 298, 301–305, 308–309, 311–314, 316, 319–324, 327, 329–337, 342–349, 352, 354–362, 366–370, 372, 375–376, 378–382, 385–386, 388–391, 393, 395–400, 402–404, 406–408, 410–413, 415, 418–424, 426–429, 432–433, 436–439, 442, 445–446, 448–450, 453, 455–456, 459–460, 462–468, 471–472, 474–476, 478–481, 483, 64, 75–77, 83–86, 95
src/agents
dev.ts	15%	100%	0%	15.79%	10–20, 5–9
reviewer.ts	5.88%	100%	0%	5.93%	100–149, 23–99
sm.ts	18.75%	100%	0%	20%	10–16, 5–9
story-creator.ts	15%	100%	0%	15.79%	10–21, 6–9
src/claude
cli.ts	4.26%	100%	0%	4.35%	10–59, 6, 60–69, 7, 70–79, 8, 80, 84–89, 9, 90–96
prompts.ts	12.90%	100%	0%	15.38%	1, 20–31, 39–42, 55–58, 83
src/git
commit.ts	4.35%	100%	0%	4.55%	10–28, 32–39, 4, 40–41, 46–49, 5, 50–59, 6, 60–69, 7, 70–79, 8, 80, 84–89, 9, 90–97
src/ui
agent-line.ts	100%	100%	100%	100%
banner.ts	100%	100%	100%	100%
celebration.ts	100%	100%	100%	100%
error.ts	100%	100%	100%	100%
index.ts	100%	100%	100%	100%
phase-header.ts	100%	100%	100%	100%
progress.ts	100%	100%	100%	100%
status.ts	100%	100%	100%	100%
story-card.ts	100%	100%	100%	100%
unicode-support.ts	100%	100%	100%	100%
src/utils
files.ts	21.67%	100%	10.53%	22.29%	100–152, 156–172, 177–217, 22, 221–227, 23, 232–235, 24–28, 287–288, 29, 290, 293, 295–299, 30, 300–304, 306, 31, 343–358, 36, 365–369, 37, 370–379, 38, 380, 388–389, 39, 390–399, 40, 400–409, 41, 410–423, 46–48, 52–57, 62–81, 85–99
logger.ts	39.64%	100%	20%	42.71%	104, 11, 111, 126–146, 23–24, 29–30, 34, 37–38, 43, 51, 59, 63–69, 7, 73–76, 80–81, 91–97
stream-wrapper.ts	100%	100%	100%	100%
timer.ts	22.50%	100%	20%	22.86%	14–28, 35–40, 50, 61, 69–72
user-input.ts	20.69%	100%	28.57%	20%	10–20, 24–33, 39, 4, 40–49, 5, 50–56, 6, 60–69, 7, 73–79, 8, 80–81, 9