docs(agents): tooling-improvement and architecture-upkeep rules; add tool tests

Researched the sibling project's tooling discipline (tools/README inventory,
tools/tests with stdlib unittest, check_docs gate, clean-worktree rule, paid-API
tools human-triggered) and encoded it for this repository:

AGENTS.md gains two sections.
- 'Python and shell tooling': fix the tool not the artefact; improve over fork;
  one script one job; fail loudly; result files for Unreal commandlets; absolute
  paths into sandboxes; clean worktree for generators (.blend/.umap are
  read-only on checkout); network/paid tools human-triggered with 429 back-off;
  measure don't assert; document every tool in the README inventory; test the
  pure parts.
- 'Architecture documentation': Docs/Architecture is arc42 in Markdown; a table
  mapping each kind of change to the section that must be updated; describe what
  exists, ADRs append-only, keep architecture.md in sync, prettier --check.

Made the referenced scaffolding real rather than aspirational:
- Tools/tests/ (README + __init__) with 12 passing unittest tests covering
  input_emulation's ioctl/key-code encoding and block_height_report's height
  classification.
- requirements-tools.txt (requests).
- Extracted classify_height() out of block_height_report.main() so the roof/
  shelter rule is testable — the rule itself came from the v0.1.2 finding.
- Tools/README: tests section, input-injection rows, and the removed TEMP-QA row
  replaced by the real cvar/self-test description.
- Docs/Architecture 05 + architecture.md: tools table extended (input injection,
  tests) and a link to the tool rules; kept in sync per the new rule.

Tools/README.md

@@ -57,4 +57,21 @@ Geographic tools live in [`Geo/tools/`](../Geo/README.md) and the Blender-side b
 | Command | Purpose |
 | --- | --- |
 | `UnrealEditor <uproject> /Game/Hollywood/DemoMap -game -qaselftest` | Headless behaviour check: drives forward input for 2 s, then resets and pauses. Logs `GigLine QA: ... PASS/FAIL` lines and a final `RESULT`. Runs only with `-qaselftest`, so normal play is unaffected. |
-| `GigLine SIM` / `GigLine GROUND` log lines | Emitted every second by `AGigLineCharacter` (TEMP QA): position, fall state, movement mode, and what the ground probe hits underneath. Remove before release. |
+| `-qaselftest` phases | Walk, reset, pause/unpause, a 16-row seam transect (0 holes) and a ground-referenced wall probe (0/35), plus a frame-time capture writing `Saved/Profiling/perf-walk-frametimes.csv` and logging `GigLine PERF:`. |
+| `gigline.SetupLogs` cvar | Spawn/input setup logging, **off by default** (`DefaultEngine.ini [ConsoleVariables]`); enable at runtime with `gigline.SetupLogs 1`. |
+
+## Input injection
+
+| Tool | Purpose |
+| --- | --- |
+| `input_emulation.py` | Pure-stdlib `ctypes`/`fcntl` driver that creates a virtual keyboard+mouse on `/dev/uinput`. The desktop treats it as real hardware, so it proves whether OS input actually reaches the game. Needs `/dev/uinput` writable (ACL on this host). |
+| `input_test.py` | Injects a scripted sequence into the focused window: `--sequence move:2,look:3,jump:1,reset:1,pause:1,click`. |
+
+## Tests
+
+```bash
+python3 -m pip install -r requirements-tools.txt
+python3 -m unittest discover -s Tools/tests -t Tools -p 'test_*.py'
+```
+
+Stdlib `unittest`, no Blender/Unreal process. See [`tests/README.md`](tests/README.md): test the pure parts (encoding, classification, maths, parsing); if logic is buried in `main()`, extract it into a function so it can be tested.