Stop tracking two laptop builds

./bridge and ./opnet-watcher/opnet-watcher are Mach-O arm64 executables that
rode into feature commits from someone's machine. Nothing deploys them — every
target is linux — and 24MB of the two is carried in every clone. What they
actually cost is the shared checkout: a local `go build ./cmd/bridge/` dirties
a tracked file, and a dirty tracked file refuses the next person's pull.

Untracked and ignored. The files stay on disk; only git stops watching them.

.gitignore

@@ -85,3 +85,9 @@ AGENTS.md
 GEMINI.md
 GROK.md
 QWEN.md
+
+# Compiled binaries: these were macOS arm64 builds committed from a laptop,
+# which no deploy can run and which every local `go build` dirties — a dirty
+# tracked binary blocks the next pull in a shared checkout.
+/bridge
+/opnet-watcher/opnet-watcher