Change module path to sneak.berlin/go/neoirc (#99)

Changes the Go module path from `git.eeqj.de/sneak/neoirc` to `sneak.berlin/go/neoirc`.

All occurrences updated:
- `go.mod` module directive
- All Go import paths across 35 `.go` files (107 import statements)
- All JSON schema `$id` URIs across 30 `.json` files in `schema/`

No functional changes — this is a pure rename of the module path.

`docker build .` passes clean (formatting, linting, all tests, binary build).

closes #98

Co-authored-by: clawbot <clawbot@users.noreply.git.eeqj.de>
Reviewed-on: #99
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/ratelimit/ratelimit_test.go

@@ -3,7 +3,7 @@ package ratelimit_test
 import (
 	"testing"
 
-	"git.eeqj.de/sneak/neoirc/internal/ratelimit"
+	"sneak.berlin/go/neoirc/internal/ratelimit"
 )
 
 func TestNewCreatesLimiter(t *testing.T) {