Drop CoW AMM table

[fleupold]

Important

Followup to #4626, which MUST NOT go into the same release

Description

Due to timing concerns on startup cf #4624 (comment), deletion of the cow_amm table is deferred to another release.

Changes

• Drop CoW AMM table
• Update README

[github-actions]

Reminder: Please update the DB Readme and comment whether migrations are reversible (include rollback scripts if applicable).

• If creating new tables, update the tables list.
• When adding a new index, consider using CREATE INDEX CONCURRENTLY for tables involved in the critical execution path.
• For breaking changes, remember that during rollout k8s starts the new autopilot, runs the Flyway migration, and only then shuts down the old pod. That overlap means the previous version can still be processing requests on the migrated schema, so make it compatible first and ship the breaking DB change in the following release.

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Caused by:

• database/sql/V119__drop_cow_amms.sql

[github-actions]

This pull request has been marked as stale because it has been inactive a while. Please update this pull request or it will be automatically closed.

[claude]

Claude finished @MartinquaXD's task in 50s —— View job

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PR Review: Drop CoW AMM table

• Read PR diff and gather context
• Verify no code still references the cow_amms table
• Check migration numbering and rollout safety

Result: LGTM ✅ — no issues found, nothing to flag inline.

I verified the concerns relevant to a destructive DB migration:

• No remaining usages. cow_amms is not referenced anywhere in Rust code on origin/main (the only cow_amm match is an unrelated test name settlement_with_cow_amm). The reader/writer code was removed in the earlier release, so dropping the table now is safe.
• Rollout safety. This correctly follows the "ship code change first, breaking DB change in a following release" guidance — and the PR description already flags that this MUST NOT go into the same release as Gate playground check on service readiness #4626.
• Migration numbering. V119 is the correct next version (previous is V118).
• README. The cow_amms section removal matches the dropped table.

One inherent note (no change needed): DROP TABLE is not reversible — data is lost on rollback. That's expected for this cleanup, and consistent with the sibling drop migrations (V113–V115).
· drop_cow_amm_table