Split Rust and Go lookup codecs

Author: ktsaou

.agents/sow/current/SOW-0014-20260603-maintainability-hotspots.md

@@ -1150,6 +1150,59 @@ Raw cache, Go typed-facade, apps lookup builder, cgroups lookup builder, apps lo
   - End-user/operator skills: no update needed because exported/operator workflow is unchanged.
   - SOW lifecycle: target remains part of active `SOW-0014`; SOW remains in progress pending metric re-check and next selected hotspot.
 
+### 2026-06-04 Rust And Go Lookup Codec File Split
+
+- The user requested continuing the code-organization fix after the C protocol split.
+- Implemented Rust and Go source splits to match the approved rule that each service-kind codec owns its own implementation file:
+  - Rust `src/crates/netipc/src/protocol/lookup.rs` is now a small module wrapper.
+  - Rust shared lookup helpers live in `src/crates/netipc/src/protocol/lookup/common.rs`.
+  - Rust cgroups lookup implementation lives in `src/crates/netipc/src/protocol/lookup/cgroups_lookup.rs`.
+  - Rust apps lookup implementation lives in `src/crates/netipc/src/protocol/lookup/apps_lookup.rs`.
+  - Go `src/go/pkg/netipc/protocol/lookup.go` is now a package stub retained to avoid deleting the file.
+  - Go shared lookup helpers live in `src/go/pkg/netipc/protocol/lookup_common.go`.
+  - Go cgroups lookup implementation lives in `src/go/pkg/netipc/protocol/cgroups_lookup.go`.
+  - Go apps lookup implementation lives in `src/go/pkg/netipc/protocol/apps_lookup.go`.
+  - Go `src/go/pkg/netipc/protocol/lookup_test.go` was left unchanged in this pass because its largest remaining mixed tests deliberately exercise shared lookup validation, bounds, and dispatch behavior across both lookup codecs.
+  - `docs/code-organization.md` now reflects the Rust and Go protocol layout.
+- Size result:
+  - Rust before: `src/crates/netipc/src/protocol/lookup.rs` had 1987 lines.
+  - Rust after:
+    - `src/crates/netipc/src/protocol/lookup.rs`: 9 lines.
+    - `src/crates/netipc/src/protocol/lookup/common.rs`: 382 lines.
+    - `src/crates/netipc/src/protocol/lookup/cgroups_lookup.rs`: 755 lines.
+    - `src/crates/netipc/src/protocol/lookup/apps_lookup.rs`: 886 lines.
+  - Go before: `src/go/pkg/netipc/protocol/lookup.go` had 1493 lines.
+  - Go after:
+    - `src/go/pkg/netipc/protocol/lookup.go`: 1 line.
+    - `src/go/pkg/netipc/protocol/lookup_common.go`: 469 lines.
+    - `src/go/pkg/netipc/protocol/cgroups_lookup.go`: 475 lines.
+    - `src/go/pkg/netipc/protocol/apps_lookup.go`: 553 lines.
+- Validation:
+  - `cargo fmt --manifest-path src/crates/netipc/Cargo.toml -- --check` passed.
+  - `cargo test --manifest-path src/crates/netipc/Cargo.toml` passed: 332 Rust unit tests passed, plus bin/doc test targets.
+  - `go test -C src/go ./pkg/netipc/protocol` passed.
+  - `go test -C src/go ./...` passed for all Go module packages, including the longer raw service tests.
+  - `bash tests/interop_codec.sh` passed:
+    - Rust decoded C output: 89 passed, 0 failed.
+    - Go decoded C output: 90 passed, 0 failed.
+    - C decoded Rust output: 101 passed, 0 failed.
+    - Go decoded Rust output: 90 passed, 0 failed.
+    - C decoded Go output: 101 passed, 0 failed.
+    - Rust decoded Go output: 89 passed, 0 failed.
+    - C, Rust, and Go generated byte-identical protocol fixture files.
+  - `make` passed for the full local build.
+  - `/usr/bin/ctest --test-dir build --output-on-failure` passed: 46/46 tests.
+  - `codacy-analysis analyze --output-format json` passed with 0 issues and 0 errors across Checkov, Opengrep/Semgrep, Trivy, cppcheck, ShellCheck, and Spectral.
+  - `git diff --check` passed.
+  - `bash .agents/sow/audit.sh` passed and reported SOW initialization complete and clean.
+- Artifact impact:
+  - `AGENTS.md`: no workflow or guardrail change.
+  - Runtime project skills: no reusable workflow change.
+  - Specs: no update needed because public protocol/API behavior and wire bytes are unchanged.
+  - End-user/operator docs: `docs/code-organization.md` updated because repository layout changed.
+  - End-user/operator skills: no update needed because exported/operator workflow is unchanged.
+  - SOW lifecycle: target remains part of active `SOW-0014`; SOW remains in progress pending metric re-check and next selected hotspot.
+
 ## Lessons Extracted
 
 Pending.

docs/code-organization.md

@@ -43,14 +43,23 @@ src/
 
   crates/netipc/              # Rust library (Cargo crate)
     src/
-      protocol.rs             # Codec
+      protocol/               # Codec
+        mod.rs                # Core wire primitives and codec re-exports
+        lookup/               # Lookup codec family
+          common.rs           # Shared lookup helpers
+          cgroups_lookup.rs   # cgroups lookup codec
+          apps_lookup.rs      # apps lookup codec
       transport/
         posix.rs              # L1: UDS, SHM
         windows.rs            # L1: Named Pipe, SHM
       service/                # L2/L3: typed client/server helpers
 
   go/pkg/netipc/              # Go library (Go package)
     protocol/                 # Codec
+      frame.go                # Core wire primitives
+      lookup_common.go        # Shared lookup helpers
+      cgroups_lookup.go       # cgroups lookup codec
+      apps_lookup.go          # apps lookup codec
     transport/
       posix/                  # L1: UDS, SHM
       windows/                # L1: Named Pipe, SHM