feat. rebuild service in Go

Rebuild the Gitea Codex review bot from the product contract with a Go HTTP service, durable SQL queue, typed Gitea client, isolated runner, and deployment updates.

Co-Authored-By: Claude <noreply@anthropic.com>

go.mod

@@ -0,0 +1,23 @@
+module gitea-codex-bot
+
+go 1.25
+
+require (
+	github.com/go-sql-driver/mysql v1.9.3
+	gopkg.in/yaml.v3 v3.0.1
+	modernc.org/sqlite v1.39.1
+)
+
+require (
+	filippo.io/edwards25519 v1.1.0 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/ncruces/go-strftime v0.1.9 // indirect
+	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	golang.org/x/exp v0.0.0-20250620022241-b7579e27df2b // indirect
+	golang.org/x/sys v0.36.0 // indirect
+	modernc.org/libc v1.66.10 // indirect
+	modernc.org/mathutil v1.7.1 // indirect
+	modernc.org/memory v1.11.0 // indirect
+)