Fix equity trust valuation misclassification

[cursor]

Bug and impact

Equities whose names contain "Trust" (for example REITs like Digital Realty Trust) were misclassified as ETF/index instruments. Their valuation runs skipped the single-company DCF/comps path and persisted ETF-style relative regime outputs with DCF forced to zero.

Root cause

The ETF/index detector treated broad name keywords, including TRUST, as sufficient even when quote metadata identified the instrument as EQUITY.

Fix

• Removed standalone TRUST from ETF/index name matching.
• Let explicit ETF/fund metadata still win, but treat explicit equity/common-stock metadata as single-company valuation before falling back to name heuristics.
• Added a regression test for an equity named Digital Realty Trust, Inc..
• Aligned an existing valuation bridge assertion with the function's rounded cent-level output.

Validation

• python3 -m unittest backend.tests.test_valuation_summary