-- Grid → Pipeline adoption — a durable link from a fundraising-grid investor to its
-- Pipeline opportunity row.
--
-- ADDITIVE + REVERSIBLE (CLAUDE.md guardrail #3): adds one nullable column + index.
-- Until now the grid's "Create Opportunity" button fired a one-shot POST with no
-- back-reference, so a grid investor could spawn unlimited duplicate opportunities and
-- an opp never knew which grid row it belonged to. opportunities.fundraising_investor_id
-- records the link (set by the new POST /api/fundraising/pipeline/link endpoint), making
-- the relationship dedup-able and reconcilable. "Is this investor in the pipeline?" and
-- "what stage?" are then DERIVED from a live join on this column — deliberately not a
-- denormalized mirror flag on fundraising_investors, which would only reintroduce the
-- two-model drift this CRM exists to fight.
--
-- fundraising_investor_id is a LOGICAL foreign key to fundraising_investors(id). It is
-- intentionally NOT a declared SQLite FOREIGN KEY: opportunities are soft-deleted (never
-- hard-deleted) and fundraising_investors rows are rebuilt on every grid save, so there
-- is nothing to cascade; SQLite's ALTER TABLE ADD COLUMN cannot add an enforced FK
-- cleanly anyway. Nullable so every existing opportunity stays valid — a manually-created,
-- non-grid opportunity simply has NULL here.
ALTER TABLE opportunities ADD COLUMN fundraising_investor_id TEXT;

CREATE INDEX IF NOT EXISTS idx_opportunities_fr_investor ON opportunities(fundraising_investor_id);