chore(go): bump toolchain 1.25.5 -> 1.25.7 to close stdlib CVEs

Block 6's new govulncheck gate flagged two crypto/tls CVEs
(GO-2026-4340, GO-2026-4337) in the 1.25.5 stdlib. 1.25.7 carries
both fixes. Bump go.mod directive so setup-go picks the patched
toolchain in CI.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: aksOps

go.mod

@@ -1,6 +1,6 @@
 module github.com/RandomCodeSpace/docsiq
 
-go 1.25.5
+go 1.25.7
 
 require (
 	github.com/google/uuid v1.6.0