Add institutional ownership tools with investor name resolution

[ChrisPachulski]

Summary

• Adds get_institutional_ownership_by_ticker and get_institutional_ownership_by_investor tools backed by SEC 13-F data
• Investor names are automatically resolved from natural language (e.g. "Scion Asset Management") to the API's UPPERCASE_WITH_UNDERSCORES format via a cached investor list + fuzzy matching (exact → suffix → substring, preferring shortest match)
• Registers both tools in the financial_search router with prompt guidance so the LLM passes plain-English investor names and lets the tool handle resolution

Details

4 files changed:

File	Change
src/tools/finance/api.ts	Added getInvestorList() — lazy in-memory cache of ~10k investor names from /institutional-ownership/investors/
src/tools/finance/institutional-ownership.ts	New file — both tools + resolveInvestorName() (normalize → exact → suffix → substring matching)
src/tools/finance/financial-search.ts	Import, router entries, section 4 prompt guidance, description update
src/tools/finance/index.ts	Re-export the new tools

Name resolution strategy:

1. Normalize input to UPPERCASE_WITH_UNDERSCORES
2. Exact match against investor list
3. Try common suffixes (_LLC, _INC, _LP, etc.)
4. Substring match (prefer shortest/most-specific)
5. Pass through on no match (let API return error)

Test plan

• bun run typecheck passes
• bun test — existing tests unaffected
• Manual: "Who owns AAPL?" routes to get_institutional_ownership_by_ticker
• Manual: "What does Berkshire Hathaway own?" resolves to BERKSHIRE_HATHAWAY_INC and returns holdings