gainium-dev-flow

Gainium-specific development workflow — spec-driven gates for every change (feature or bug fix), with a bug-flavored spec template (definition, evidence, assumption) and a blast-radius-checking plan when the standard feature template doesn't fit, SOLID applied per this repo's own architectural pattern, and just-in-time extraction of legacy spaghetti (domain logic mixed with I/O) instead of full rewrites. Use…