feat(understand): the plant pack, lean 65, five-language aliases, eight golden queries and the counts

The three track-H branches are merged; this is the integration that makes the
six tools one surface.

- TOOL_PACK_NAMES gains "plant" (pipe_takeoff, cable_takeoff); SECTION 26's
  four readers stay core. Lean gains drawing_understand and reaches 65 (55
  with TOOL_PACKS=core). The `understand` and `plant` tags rank after `arch`,
  so the sections file as `understanding` (4) and `plant` (2): 247 tools in
  28 groups.
- discovery/aliases.py folds spec section 12's vocabulary into the six records
  the branches wrote - metraj, metre cetveli, boru / kablo listesi, fark,
  karsilastir, revizyon farki, olcek, birim in both Turkish spellings, BOQ,
  takeoff, scale check, COMPARE - without writing a phrase twice. The Russian
  terms are data only: the BM25 tokenizer keeps [a-z0-9], and no golden case
  pretends otherwise.
- Eight golden tuning cases, four of them Turkish; the shared-command
  allowlist reconciled with what the merged records claim; the token-suite
  formula excludes the new pack; the inventory regenerated, the registry
  snapshot retaken and the README figures taken from check_doc_numbers.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd

tests/test_token_suite.py

@@ -163,9 +163,9 @@ def test_the_cache_arithmetic_follows_the_published_multipliers():
 
 def test_the_idle_lane_covers_the_five_advertised_surfaces(report):
     """Default, lean, search - and the two single-vertical clients:
-    TOOL_PACKS=core,mech (the default surface minus exactly the pid and settings
-    packs, and the arch pack) and TOOL_PACKS=core,arch (minus pid, settings and
-    mech)."""
+    TOOL_PACKS=core,mech (the default surface minus exactly the pid, settings,
+    arch and plant packs) and TOOL_PACKS=core,arch (minus pid, settings, mech
+    and plant)."""
     variants = {row["variant"]: row for row in report["idle"]}
     assert set(variants) == {"default", "lean", "packs_core_mech", "packs_core_arch", "search"}
     assert variants["default"]["advertised_tools"] > 100
@@ -177,12 +177,14 @@ def test_the_idle_lane_covers_the_five_advertised_surfaces(report):
         - len(packs["pid"])
         - len(packs["settings"])
         - len(packs["arch"])
+        - len(packs["plant"])
     )
     assert variants["packs_core_arch"]["advertised_tools"] == (
         variants["default"]["advertised_tools"]
         - len(packs["pid"])
         - len(packs["settings"])
         - len(packs["mech"])
+        - len(packs["plant"])
     )
     for narrowed in ("packs_core_mech", "packs_core_arch"):
         assert (