Enforce default ±2 month gig-spacing in getCandidates and add date fallback parsing

[JoshuaVSherman]

Summary

• Enforces DEFAULT_GIG_SPACING_MONTHS = 2 in OutreachController.excludeUpcomingGigVenues and OutreachController.buildCandidateReason when a venue's gigInterval is 0 or unset (null/undefined), preventing candidates with nearby booked gigs from being pitched by default.
• Respects explicit custom gigInterval values > 0 (e.g. 3, 6) when configured on a venue document.
• Updates buildCandidateReason to evaluate spacing against gigIntervalMonths (defaulting to 2) and formats spacingNote as 'no gigs yet' when no gigs exist, or 'clear — nearest gig ~X mo away' when gigs are spaced adequately.
• Adds parseTargetDates helper and updates parseTargetWeekend to parse ISO start and end dates from targetDates strings (e.g. 2026-10-16 to 2026-10-18, 2026-10-16 - 2026-10-18, 2026-10-16) when targetWeekend object is not provided in req.query.
• Updates unit tests in test/unit/outreach/outreach-controller.spec.ts to assert the default 2-month spacing behavior and test targetDates fallback parsing.
• Bumps package version to 2.11.10.

Closes #1036

How to test locally

1. Unit test verification:
   • Run npx vitest run test/unit/outreach/outreach-controller.spec.ts to verify all candidate spacing and targetDates fallback tests pass.
2. Behavioral verification of default 2-month spacing:
   • Create a test venue with gigInterval: 0 (or unset) and a gig 1 month away from target window w. Verify GET /outreach/candidates excludes the venue.
   • Create a test venue with gigInterval: 0 (or unset) and a gig 3 months away from w. Verify GET /outreach/candidates includes the venue with reason.gigIntervalMonths: 2 and reason.spacingNote: 'clear — nearest gig ~3 mo away'.
   • Create a test venue with explicit gigInterval: 3 and a gig 2.5 months away from w. Verify GET /outreach/candidates excludes the venue.
3. Behavioral verification of targetDates string fallback:
   • Send GET /outreach/candidates?targetDates=2026-10-16 to 2026-10-18.
   • Verify w resolves to 2026-10-16 and candidate filtering properly excludes venues with gigs in September 2026.
4. Run full test suite and linters:
   • npm run test:lint
   • npm run typecheck
   • npm run jscpd
   • npm test

Test evidence

> npm run test:lint
> eslint ./src --fix

> npm run typecheck
> tsc --noEmit -p tsconfig.prod.json && tsc --noEmit

> npm run jscpd
Found 39 clones.
time: 15.241ms

> npm test
 ✓ test/unit/outreach/outreach-controller.spec.ts (225 tests) 828ms
 Test Files  55 passed (55)
      Tests  1076 passed (1076)
   Duration  40.48s
Coverage: Statements: 94.19%, Branches: 87.23%, Functions: 84.53%, Lines: 94.51%

🤖 Work by Antigravity — Gemini Flash (Medium)