docs(03-02): complete secondary sports canonicalization plan

Tasks completed: 3/3
- Add MLS to canonicalization pipeline (30 teams + 10 aliases + 8 stadium aliases)
- Add WNBA to canonicalization pipeline (13 teams + 6 aliases + 4 stadium aliases)
- Add NWSL to canonicalization pipeline (13 teams + 7 aliases + 3 stadium aliases)

Phase 3 complete - all 7 sports now have alias support (180 teams total)

SUMMARY: .planning/phases/03-alias-systems/03-02-SUMMARY.md

.planning/phases/03-alias-systems/03-02-SUMMARY.md

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+---
+phase: 03-alias-systems
+plan: 02
+subsystem: data-pipeline
+tags: [mls, wnba, nwsl, canonicalization, aliases, teams, stadiums]
+
+# Dependency graph
+requires:
+  - phase: 02.1-additional-sports-stadiums
+    provides: MLS_TEAMS, WNBA_TEAMS, NWSL_TEAMS dicts with stadium data
+  - phase: 03-alias-systems/03-01
+    provides: NFL canonicalization patterns, division mapping approach
+provides:
+  - MLS teams canonicalized (30 teams in Eastern/Western conferences)
+  - WNBA teams canonicalized (13 teams)
+  - NWSL teams canonicalized (13 teams)
+  - Team abbreviation aliases for all secondary sports
+  - Stadium historical aliases for all secondary sports
+affects: [04-canonical-linking, game-resolution, stadium-matching]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns: [conference-only-divisions, shared-venue-aliases]
+
+key-files:
+  created: []
+  modified:
+    - Scripts/canonicalize_teams.py
+    - Scripts/canonicalize_games.py
+    - Scripts/canonicalize_stadiums.py
+
+key-decisions:
+  - "MLS/WNBA/NWSL use conference-only structure (no divisions) - mapped to (conference, None)"
+  - "WNBA/NWSL share venues with NBA/MLS - minimal new stadium aliases needed"
+  - "Added arena_key='arena' for WNBA to match venue field naming"
+
+patterns-established:
+  - "All 7 sports now follow consistent canonicalization patterns"
+  - "Conference-only sports use (conference_id, None) for division mapping"
+
+issues-created: []
+
+# Metrics
+duration: 5 min
+completed: 2026-01-10
+---
+
+# Phase 3 Plan 02: Secondary Sports Canonicalization Summary
+
+**MLS, WNBA, NWSL added to canonicalization pipeline with 56 total new teams, 23 abbreviation aliases, and 15 stadium aliases**
+
+## Performance
+
+- **Duration:** 5 min
+- **Started:** 2026-01-10T15:38:30Z
+- **Completed:** 2026-01-10T15:43:56Z
+- **Tasks:** 3
+- **Files modified:** 3
+
+## Accomplishments
+- MLS canonicalized with 30 teams (Eastern/Western conferences) + 10 aliases + 8 stadium aliases
+- WNBA canonicalized with 13 teams + 6 aliases + 4 stadium aliases
+- NWSL canonicalized with 13 teams + 7 aliases + 3 stadium aliases
+- Total team count now 180 across all 7 sports (NBA: 30, MLB: 30, NHL: 32, NFL: 32, MLS: 30, WNBA: 13, NWSL: 13)
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Add MLS to canonicalization pipeline** - `b6a913d` (feat)
+2. **Task 2: Add WNBA to canonicalization pipeline** - `285bc07` (feat)
+3. **Task 3: Add NWSL to canonicalization pipeline** - `81f620d` (feat)
+
+**Plan metadata:** (pending)
+
+## Files Created/Modified
+- `Scripts/canonicalize_teams.py` - Added imports, division dicts, sport_mappings for MLS, WNBA, NWSL
+- `Scripts/canonicalize_games.py` - Added 23 team abbreviation aliases across 3 sports
+- `Scripts/canonicalize_stadiums.py` - Added 15 stadium historical aliases across 3 sports
+
+## Decisions Made
+- MLS/WNBA/NWSL use conference-only structure (no divisions) - mapped to (conference_id, None)
+- WNBA/NWSL share venues with NBA/MLS - only added sport-specific aliases where needed
+- Added arena_key='arena' for WNBA to match venue field naming convention
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+
+None
+
+## Next Phase Readiness
+- Phase 3 complete - all 7 sports now have alias support
+- 180 teams canonicalized with full conference/division structure
+- Ready for Phase 4: Canonical Linking
+
+---
+*Phase: 03-alias-systems*
+*Completed: 2026-01-10*