chore(deps): bump pgvector/pgvector from 0.8.6-pg15 to 0.8.7-pg15 in /compose/production/postgres

[dependabot]

Bumps pgvector/pgvector from 0.8.6-pg15 to 0.8.7-pg15.

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot show <dependency name> ignore conditions will show all of the ignore conditions of the specified dependency
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[claude]

Review: one-line patch bump of the production Postgres base image (pgvector 0.8.6-pg15 → 0.8.7-pg15). Same PG major, so no data-directory compatibility concern, and no code, security or test changes.

Notes:

• The image only changes the extension's available version. Existing databases keep the old extension until ALTER EXTENSION vector UPDATE; is run. After deploying, check SELECT extversion FROM pg_extension WHERE extname='vector'; and update if desired. Patch releases are normally drop-in, but if you have HNSW indexes, take a backup first.
• Check that the local/test compose files use a matching pgvector version, so dev and test don't drift from production.

LGTM once CI is green.