# After switching to the new same-dim model in your config:
modusbrain embed --stale          # re-embeds signature-drifted pages
modusbrain embed --stale --dry-run # preview the count without re-embedding

modusbrain reinit-pglite \
  --embedding-model zeroentropyai:zembed-1 \
  --embedding-dimensions 1280

# 1. Back up the existing brain (in case you want to roll back).
mv ~/.modusbrain/brain.pglite ~/.modusbrain/brain.pglite.bak

# 2. Re-init with the new model + dimensions. `modusbrain init` writes
#    the schema sized to the new dim, and (as of v0.37) preserves
#    every other field in ~/.modusbrain/config.json (chat model,
#    expansion model, API keys).
modusbrain init --pglite \
  --embedding-model zeroentropyai:zembed-1 \
  --embedding-dimensions 1280

# 3. Re-import your brain repo. `modusbrain sync` reads the brain repo
#    from disk and re-creates the page rows.
modusbrain sync

# 4. Re-embed. The embed pipeline now uses the new model and the
#    column accepts the new dim.
modusbrain embed --stale

BEGIN;

-- 1. Drop the HNSW index. It can't survive the column type change.
DROP INDEX IF EXISTS idx_chunks_embedding;

-- 2. Clear stale embeddings FIRST. This must happen BEFORE the column
--    alter: pgvector refuses to cast existing vectors across dimensions
--    ("expected <NEW_DIMS> dimensions, not <OLD_DIMS>"), so altering a
--    column that still holds old-width vectors aborts the transaction.
--    NULLs cast fine. (The old vectors are unusable in the new space
--    anyway — this is the wipe step from the rationale above.)
UPDATE content_chunks SET embedding = NULL, embedded_at = NULL;

-- 3. Alter the column type (all rows are NULL now, so the cast succeeds).
ALTER TABLE content_chunks ALTER COLUMN embedding TYPE vector(<NEW_DIMS>);

-- 4. Recreate the HNSW index ONLY IF dims <= 2000. Above that, leave it
--    indexless and rely on exact scans (modusbrain searchVector handles this
--    automatically — search just gets slower, not broken).
-- For dims <= 2000 (e.g. 1024, 1280, 1536, 768):
CREATE INDEX IF NOT EXISTS idx_chunks_embedding
  ON content_chunks USING hnsw (embedding vector_cosine_ops);
-- For dims > 2000 (e.g. 2048 Voyage 4 Large): skip step 4.

COMMIT;

modusbrain init --supabase \
  --embedding-model <provider:model> \
  --embedding-dimensions <NEW_DIMS>

modusbrain embed --stale

✓ embedding_width_consistency   dim parity: config 1280 / column vector(1280)