Add tax profile gap detection and annual summary

[codeforester]

Goal

Build the second TaxBuddy slice after #99: infer expected tax sources/forms, surface missing documents, and produce an annual readiness summary from indexed tax documents.

Dependencies

• Depends on Document the TaxBuddy layer in BankBuddy #98 for the accepted design.
• Depends on Add TaxBuddy document import and metadata index #99 for imported tax document metadata.

Decision

The first summary should be a tax readiness picture, not a tax filing engine. It should answer: what documents are present, what forms/sources are expected, which documents are missing or waived, and what areas need user review. A numeric tax-liability estimate should be deferred until a separate issue defines jurisdiction-specific calculation rules and disclaimers.

Scope

• Add or complete tax_sources, tax_profile, property_assets, and tax_form_gaps storage, or the normalized equivalents approved by Document the TaxBuddy layer in BankBuddy #98.
• Infer source records from imported documents, including source name, source type, jurisdiction, expected form types, active/inactive state, and account suffixes when available.
• Add explicit user override commands for sources/forms when inference is incomplete, for example adding, deactivating, or waiving an expected source/form.
• Generate annual gap rows for expected documents by tax year.
• Add taxbuddy profile show --year YEAR, taxbuddy profile sources, and taxbuddy profile gaps --year YEAR.
• Add taxbuddy summary --year YEAR with document inventory, missing/pending/waived forms, jurisdiction split, and review notes.
• Include US and India-ready shape in the model, but keep the first rules data-driven and easy to extend.

Acceptance Criteria

• Gap detection never silently fabricates certainty. Ambiguous expected forms are marked for review.
• The user can mark a missing expected document as waived or a source as inactive without deleting history.
• The annual summary is deterministic and generated from SQLite state, not a cached aggregate table.
• CLI output avoids sensitive identifiers beyond masked suffixes.
• Tests cover source inference, manual overrides, gap generation, summary output, inactive sources, waived gaps, and empty-year behavior.
• Documentation makes clear that this is organization/readiness support, not tax advice or return preparation.
• ./tests/validate.sh passes before PR review.

Out of Scope

• Numeric tax liability estimation.
• Filing integration with TurboTax, IRS, Indian tax portals, or CPA tools.
• Web UI or spouse access.
• OCR for scanned documents.

Source Context

Derived from docs/money_buddy_summary_and_action_items.md, sections 4.2, 4.6, 4.7, 4.8, and 9.