Add telemetry-ingest service and Docker updates

Introduce a new telemetry ingestion service (misc/data/service.go) that implements an HTTP server to accept telemetry payloads, validate and sanitize inputs, apply rate limiting, compute dedupe hashes, and forward records to PocketBase with token-based auth. Add module file (misc/data/go.mod) setting module telemetry-ingest and Go version 1.25.5. Update Dockerfile to use golang:1.25-alpine and remove baked-in environment defaults (so runtime envs are required), keeping the build stage and final CMD. These changes add the core ingestion logic, dependency module, and align the build image/version.

misc/data/Dockerfile

@@ -1,5 +1,5 @@
 # build stage
-FROM golang:1.23-alpine AS build
+FROM golang:1.25-alpine AS build
 WORKDIR /src
 COPY . .
 RUN go build -trimpath -ldflags "-s -w" -o /out/telemetry-ingest ./main.go
@@ -11,11 +11,4 @@ USER app
 WORKDIR /app
 COPY --from=build /out/telemetry-ingest /app/telemetry-ingest
 EXPOSE 8080
-ENV LISTEN_ADDR=":8080" \
-    MAX_BODY_BYTES="1024" \
-    RATE_LIMIT_RPM="60" \
-    RATE_BURST="20" \
-    RATE_KEY_MODE="ip" \
-    ENABLE_REQUEST_LOGGING="false" \
-    UPSTREAM_TIMEOUT_MS="4000"
 CMD ["/app/telemetry-ingest"]