fix(snmp): ship MIB parser binary in API container with pre-loaded MIBs

- Build tod-mib-parser in both poller and API Dockerfiles
- Bundle 16 standard MIBs (IF-MIB, HOST-RESOURCES, SNMPv2, etc.)
- Pass --search-path /app/mibs to parser so dependencies resolve
- Users no longer need to upload standard MIBs manually

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poller/Dockerfile

@@ -8,6 +8,7 @@ COPY . .
 # the host CPU count), which combined with the parallel Node and Python builds
 # can saturate all cores and spike RAM on a 2-core / 2-4 GB server.
 RUN CGO_ENABLED=0 GOOS=linux GOMAXPROCS=1 go build -o /poller ./cmd/poller
+RUN CGO_ENABLED=0 GOOS=linux GOMAXPROCS=1 go build -o /tod-mib-parser ./cmd/mib-parser
 
 FROM alpine:3.21
 RUN apk add --no-cache ca-certificates iproute2