Condense migrator upgrades and remove dead tables

[mkysel]

Condense migrator upgrades by replacing the monolithic gateway_envelopes table with partitioned gateway_envelopes_meta/gateway_envelope_blobs, add payers, and update blockchain_messages foreign keys

Replace the single gateway_envelopes table with partitioned metadata and blob tables plus a join view, add payers, update triggers and indexes to target gateway_envelopes_meta, adjust blockchain_messages to reference gateway_envelopes_meta, and add block_hash to latest_block. Remove obsolete migrations and rename shard-related migrations for clarity.

📍Where to Start

Start with the schema definition in 00001_init-schema.up.sql, then review foreign key and index updates in 00004_add_blockchain_columns.up.sql and 00005_gateway_indexes.up.sql.

---

📊 Macroscope summarized a7c21dd. 0 files reviewed, 0 issues evaluated, 0 issues filtered, 0 comments posted

🗂️ Filtered Issues

No issues evaluated.

[graphite-app]

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• Queue - adds this PR to the back of the merge queue
• Hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.