docs: sync docs with code; fix Makefile modules target

Makefile:
- Add reconciler and ingest to the `modules` target; they were only built
  as side-effects of `make node`, making `make modules` incomplete

planning.md:
- Add 4 missing CLI drivers: discovery_cli, config_cli, protocol_cli,
  query_cli (all existed in code and dev/cli/Makefile but were absent)
- Add header-only utilities table: stream_stats.h, v4l2_fmt.h

README.md:
- Add transport_cli, discovery_cli, config_cli, protocol_cli, query_cli
  to CLI tools list

conventions.md:
- Add ERR_NOT_FOUND to Error_Code enum example
- Replace placeholder Invalid_Error_Detail with actual fields
  (config_line, message) that have been in use since config module
- Add missing error macros: APP_INVALID_ERROR, APP_INVALID_ERROR_MSG,
  APP_NOT_FOUND_ERROR
- Update directory structure: node/ description (was "later"), add web/
  and tools/ entries

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

planning.md

@@ -84,6 +84,10 @@ Each module gets a corresponding CLI driver that exercises its API and serves as
 | `media_ctrl_cli` | `media_ctrl` | List media devices, show topology, configure pad formats |
 | `v4l2_ctrl_cli` | `v4l2_ctrl` | List controls, get/set values — lightweight `v4l2-ctl` equivalent |
 | `transport_cli` | `transport` | Send/receive framed messages, inspect headers |
+| `discovery_cli` | `discovery` | Announce and discover peers over UDP multicast; print found/lost events |
+| `config_cli` | `config` | Load an INI config file and print the resolved values after applying schema defaults |
+| `protocol_cli` | `protocol` | Send and receive typed protocol messages; inspect frame payloads |
+| `query_cli` | `discovery` + `protocol` | Wait for first discovered node, send ENUM_DEVICES, print results — integration smoke test |
 | `test_image_cli` | `test_image` | Generate test patterns, write PPM for visual inspection |
 | `xorg_cli` | `xorg` | Display test pattern in viewer window; exercises scale/anchor modes and text overlays |
 | `v4l2_view_cli` | V4L2 + `xorg` | Live camera viewer — auto-selects highest-FPS format, FPS/format overlay; bypasses node system |
@@ -92,6 +96,15 @@ Each module gets a corresponding CLI driver that exercises its API and serves as
 | `reconciler_cli` | `reconciler` | Simulated state machine experiment — define resources with fake transitions, drive reconciler via CLI commands; validates the generic reconciler before wiring into the node |
 | `controller_cli` | `transport` + `protocol` + `discovery` | Interactive controller REPL — connects to nodes by peer index or host:port; supports enum-devices, enum-controls, get/set-control, start-ingest, stop-ingest, start-display, stop-display; readline + discovery integration; **temporary dev tool** — will be superseded by a dedicated `controller` binary that holds simultaneous connections to all peers |
 
+### Header-only utilities (`include/`)
+
+Not modules (no `.c` or Makefile) but public interfaces used across CLI tools and the node:
+
+| Header | Used by | Notes |
+|---|---|---|
+| `stream_stats.h` | `stream_send_cli`, `stream_recv_cli` | Per-stream rolling fps/Mbps stats; single-header, no dependencies |
+| `v4l2_fmt.h` | `ingest`, `v4l2_view_cli` | V4L2 format enumeration — (pixfmt, size, fps) combinations, best-format selection |
+
 ### Web UI (`dev/web/`)
 
 A Node.js/Express development web UI that connects to running video nodes as a binary protocol peer. Exposes V4L2 control inspection and adjustment, media topology view, and stream state through a browser interface. Supports live peer discovery via SSE — discovered nodes appear automatically in the UI.