feat(server): settings pack — 22 environment tools behind TOOL_PACKS, lean grows to 55, three groups, golden set +10

Task 24 (merge sanity) on main after the five track E groups merged.

- TOOL_PACK_NAMES = ("core", "pid", "settings"); PACK_TOOL_NAMES["settings"]
  is exactly the 22 SECTION 20 tools. Styles and page setup stay in core.
- LEAN_TOOL_NAMES += page_setup_apply, batch_plot (53 -> 55).
- _GROUP_TAG_PRIORITY / _GROUP_TAG_LABELS: "style" moved up next to "pid",
  "pagesetup" -> page_setup and "environment" -> environment added; the 28
  SECTION 19/20 decorators gain their section tag, so _tool_groups() reports
  styles 10 / page_setup 6 / environment 22 (23 groups, 204 tools) and
  pack == group == section for the settings pack.
- SECTION headers, backends/base.py composition, contracts/__init__.py
  exports and the layer_states feature entry were already correct after the
  merge (read and confirmed, nothing edited).
- Pack text: config.py, .env.example, README config row; README <sub> line
  204 tools in 23 groups; release snapshot 3259 collected tests (measured).
- docs/tool-inventory.json regenerated; registry snapshot re-derived.
- tests: test_tool_packs.py replaced (11 tests), test_capability_contract.py
  +3 (composition, the agreed capability flags, layer_states honesty),
  golden set +10 tuning cases (81 = 66 tuning + 15 holdout); all ten route
  in the top 3 without alias edits.

Deviation from the plan text: TRACK_E_KEYS carries five keys, not six. The
plan's "mleaderstyle" (ezdxf True / com False) contradicts spec §8.1, which
retracted that key because the ActiveX route exists (§4.2); measured on the
tree: capability_keys() == {boundary_trace, chspace, interactive_prompt,
live_application, preferences, revcloud, wipeout}, and
ComBackend.mleaderstyle_create is a native implementation
(backends/com_backend.py:6752, is_capability_default -> False). The test now
also asserts the key is absent.

No new ActiveX call was written in this task, so no live probe was needed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd

tests/data/discovery_golden.py

@@ -1,6 +1,6 @@
 """Golden query set for tool discovery: English in, one right tool out.
 
-Seventy-one cases (56 tuning + 15 holdout) split into a **tuning** set and a
+Eighty-one cases (66 tuning + 15 holdout) split into a **tuning** set and a
 **holdout** set. The split is
 the point of the file. Ranking work is measured against
 :data:`TUNING_CASES` only; :data:`HOLDOUT_CASES` were written at the same time,
@@ -155,6 +155,25 @@ TUNING_CASES: tuple[GoldenCase, ...] = (
     ),
     GoldenCase("create a text style that uses the isocp font", "textstyle_create", "paraphrase"),
     GoldenCase("which dimension styles are defined", "dimstyle_list", "counting", risk="read"),
+    # v1.6 track E — styles, page setup, templates, environment. Written
+    # before the alias records were measured against them; a miss here is
+    # fixed by adding vocabulary to the tool's record in discovery/aliases.py,
+    # never by moving the expectation.
+    GoldenCase("PAGESETUP", "page_setup_apply", "command"),
+    GoldenCase("PUBLISH", "batch_plot", "command"),
+    GoldenCase("MLEADERSTYLE", "mleaderstyle_create", "command"),
+    GoldenCase("STYLE", "textstyle_create", "command"),
+    GoldenCase("iso 25 dimension style", "dimstyle_create", "synonym"),
+    GoldenCase("layer snapshot", "layer_state_save", "synonym"),
+    GoldenCase("save this drawing as a template", "drawing_template_save", "paraphrase"),
+    GoldenCase("switch to the other open drawing", "document_activate", "paraphrase"),
+    GoldenCase("ask the operator to click a point on screen", "user_pick_point", "paraphrase"),
+    GoldenCase(
+        "what does the LTSCALE variable mean",
+        "system_variable_describe",
+        "counting",
+        risk="read",
+    ),
 )