perf(ci): turn off Postgres durability in integration tests

TRUNCATE-everything ResetDB before every test forces a commit fsync; the CI DB is rebuilt each run so durability buys nothing. ALTER SYSTEM via docker exec (the services: block can't override the postgres command line). Non-fatal so a perms surprise degrades to slow, never red.

Per the playbook the operator shared from another project (~17x speedup observed there). Measure before/after in the next two CI runs.

.gitea/workflows/test-go.yml

@@ -116,6 +116,27 @@ jobs:
           # Wait for Postgres to accept TCP (no health-check dependency).
           for i in $(seq 1 60); do (echo > "/dev/tcp/${PG_IP}/5432") 2>/dev/null && break; sleep 2; done
 
+          # Relax durability on the throwaway CI Postgres. Our test pattern
+          # is dbtest.ResetDB → TRUNCATE … RESTART IDENTITY CASCADE before
+          # every test, and the per-TRUNCATE commit fsync is the dominant
+          # cost of the integration suite. The CI DB is rebuilt every run so
+          # fsync / full_page_writes / synchronous_commit buy nothing. Apply
+          # via docker exec because:
+          #  - The act_runner `services:` block can't override the container
+          #    command, so `postgres -c fsync=off` at boot isn't an option.
+          #  - ALTER SYSTEM cannot run inside a transaction; psql -c
+          #    auto-commits each statement, which is what we need.
+          #  - fsync / full_page_writes are sighup GUCs and
+          #    synchronous_commit is user-context, so pg_reload_conf() picks
+          #    all three up with no restart.
+          # Non-fatal: a perms surprise degrades to "slower", never red CI.
+          docker exec "$PG_ID" psql -U minstrel -d minstrel_test \
+            -c "ALTER SYSTEM SET fsync = off" \
+            -c "ALTER SYSTEM SET synchronous_commit = off" \
+            -c "ALTER SYSTEM SET full_page_writes = off" \
+            -c "SELECT pg_reload_conf()" \
+            || echo "WARN: durability relax failed; continuing"
+
           # Apply embedded migrations to the fresh test DB, then run the
           # full suite (no -short → integration tests execute). -p 1:
           # every integration package TRUNCATEs the one shared test DB;