test(agent): controlled fixture KB + one-command fast loop for tool-calling iterations

The phase-72 iteration loop cleared the database, git-cloned the homelab repo, re-imported 38-51 documents and re-embedded per run — many minutes per iteration against a different KB every time (owner directive 2026-09-04: stop importing the homelab repo on every test run). Replace it with:

- tests/fixtures/agent_kb/: 8 hand-written markdown docs (sources 'deployments'/'homelab') whose specifics (rack7, 10.77.42.0/24, VLAN 130, rbm-8842, 17 2 * * *, obsidian-bor:2026.7.14, 18765, 18443, ...) no model can guess; read targets carry non-topical filenames so their questions do not lexically seed them (the read must actually happen)
- tests/fixtures/test_kb.dump.sql: data-only snapshot (TRUNCATE + INSERTs incl. embeddings, self-contained git_sources rows, static KB overview) — verified by round-trip checksum at build time
- scripts/load_test_kb.py: one-off rebuild (real pipeline + embeddings, ~2s) that also prints the per-question retrieval report (all 10 battery questions must be grounded)
- scripts/restore_test_kb.py: sub-second one-transaction restore (no git clone, no re-embedding)
- scripts/agent_realmodel_check.py: the gate gains --restore / --mode fixture (curated 10-question battery with one unambiguously correct tool behavior per question) / --turns N (12s micro-loop) / --concurrency / per-turn + total wall timing, and a second accuracy metric (contract accuracy: well-formed calls targeting resolvable entities) alongside the phase-72 locked executed ratio — the re-read of a seeded doc is a copy-invariant model behavior (5 variants, 0/15 flipped) that the dedupe refusal counts as a failure
- TOOL_CALLING_TESTING.md: the human-readable methodology (fast loop, design rules, metrics, copy levers + tried-and-reverted table, current standing, open design question)

Measured: restore 0.03s; micro-loop ~12s; full loop ~43-55s; concurrency 2/3 gives no gain (endpoint serializes).

tests/fixtures/agent_kb/homelab/containers/qwen38-llamacpp.md

@@ -0,0 +1,15 @@
+# Qwen 3.8 on llama.cpp (pbx-node3)
+
+The GPU box (`pbx-node3`) serves Qwen 3.8 through llama.cpp.
+
+Working launch line (verified 2026-08):
+
+    ./llama-server -m qwen3.8-30b-a3b-instruct.Q8_0.gguf \
+      -c 32768 -ngl 99 --mlock --threads 12 -sm layer \
+      --cache-type-k q8_0 --cache-type-v q8_0 \
+      --jinja --port 18180
+
+- Context 32768, KV cache q8_0/q8_0, prompt cache persisted to
+  `/srv/llamacpp/cache`.
+- First-token target is under 400 ms; sustained throughput about 28 tok/s.
+- Do not add `-ctk f16` — it doubled VRAM usage with no quality gain.

tests/fixtures/agent_kb/homelab/containers/uptime-kuma.md

@@ -0,0 +1,11 @@
+# Uptime Kuma (AIO)
+
+Uptime Kuma runs on `rack7-pbx2` as the AIO image, listening on
+**18443** with TLS terminated by `caddy-rack7`.
+
+- Health endpoint: `https://uptime.rack7.local/ping`
+- Every monitor posts to the ntfy topic `reese-uptime-7` on failure.
+- History is kept for 30 days; the database is backed up hourly to
+  `/opt/kuma/backup/`.
+- Lab-iot monitors watch every VLAN 130 device; the shelf watchdog
+  restarts the container after 3 missed checks.