Add RTK wrapper / filter for supabase db CLI

Context

Using RTK 0.39.0 with Claude Code on macOS. rtk discover over the last 30 days flags supabase db as a sustained unhandled command in Next.js + Supabase projects:

Why it matters

• supabase db push / pull: each emits long migration-summary tables (table list + colored diff hints) that share repeated columns. Easy compression target (keep migration names + counts, strip ANSI / progress).
• supabase db diff: SQL diff output is verbose; a --name-only-style summary or grouping by table would help in agent contexts.
• supabase db lint: results are usually a small set of advisor warnings repeated many times — dedup + count would be a big win.

Suggested approach

Add a supabase filter similar to existing npm / npx / vercel (proposed in #1255) filters:

• strip ANSI / spinner
• dedup + summarize advisor rows
• compress migration/diff tables (table name + counts; drop padding)

No supabase-related issue exists in the repo as of 2026-05-20 (searched supabase, supabase db, and Add RTK wrapper). Filing this so the data is on record.

Environment

• rtk 0.39.0
• macOS (Darwin 25.4.0)
• Claude Code PreToolUse hook

Start by reading the existing npm, npx, and vercel filters, then run representative supabase db push, pull, diff, and lint commands to inspect their output. Done means a supabase filter strips ANSI and spinner output and produces the proposed summaries, including deduplicated lint warnings and compact migration or diff tables.