ByteFrame previously panicked on out-of-bounds reads, which crashed
the server when parsing malformed client packets. Now sets a sticky
error (checked via Err()) and returns zero values, matching the
encoding/binary scanner pattern. The session recv loop checks Err()
after parsing to reject malformed packets gracefully.
Also replaces remaining panic("Not implemented") stubs in network
packet Build/Parse methods with proper error returns.
Add package-level documentation (doc.go) to all 22 first-party
packages and godoc comments to ~150 previously undocumented
exported symbols across common/, network/, and server/.
Re-enable the golangci-lint job in CI (disabled Oct 2025), update to
Go 1.25 and golangci-lint-action v7. Fix errcheck, gosimple S1009,
staticcheck SA4031 and SA2001 errors across 54 files. Remaining ~39
lint errors will be addressed in follow-up commits.
Import 18 network packet test files and 5 server infrastructure test
files, adapted for main branch APIs: fix config import alias (_config),
remove non-existent DevMode field, use global handlerTable instead of
per-server handlers map, and correct validateToken mock expectations
to include both token and tokenID arguments.
Adds go-sqlmock dependency for database mocking in signserver tests.
