[KM-711] Docs: drop /report from list_skills catalog examples

Follow-up to the button-only report change. The FE contract docs still showed
/report as a slash skill in the list_skills response example, contradicting the
shipped catalog (tools.py now exposes /help only).

- API_CONTRACT_BE_PYTHON.md: list_skills example -> count 1, /help only; note that
report is the Generate button (endpoint POST /tools/report still exists).
- API_ENDPOINTS_RESTRUCTURE.md: same example fix; "/help + /report only" -> "/help
only", /report added to the commented-out list.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

API_CONTRACT_BE_PYTHON.md

@@ -143,24 +143,22 @@ Response `200`:
 
 ```json
 {
-  "count": 2,
+  "count": 1,
   "tools": [
     {
       "command": "/help",
       "name": "help",
       "type": "skill",
       "description": "Show what the assistant can do and guide your next step."
-    },
-    {
-      "command": "/report",
-      "name": "report",
-      "type": "skill",
-      "description": "Generate a versioned analysis report with background, EDA, key findings, and insights."
     }
   ]
 }
 ```
 
+> The catalog is `/help` only (KM-711). `/report` was removed as a slash command —
+> report generation is a right-side **Generate** button, not a `/` command. The report
+> HTTP endpoint (`POST /api/v1/tools/report`) still exists; the button calls it.
+
 Tool item shape:
 
 ```json

API_ENDPOINTS_RESTRUCTURE.md

@@ -107,19 +107,18 @@ Static, deterministic, safe for Go to cache. (Was `GET /api/v1/tools`.)
 
 ```json
 {
-  "count": 2,
+  "count": 1,
   "tools": [
     { "command": "/help",   "name": "help",   "type": "skill",
-      "description": "Show what the assistant can do and guide your next step." },
-    { "command": "/report", "name": "report", "type": "skill",
-      "description": "Generate a versioned analysis report (background, EDA, key findings, insights)." }
+      "description": "Show what the assistant can do and guide your next step." }
   ]
 }
 ```
 
 `CommandResponse = { command, name, type, description }`, `type ∈ {skill, analytics, data_access}`.
-Catalog is `/help` + `/report` only; the `analyze_*` / `check_*` / `retrieve_*` and retired
-`/problem-statement` entries are commented out (kept for restorability), not deleted.
+Catalog is `/help` only; the `/report`, `analyze_*` / `check_*` / `retrieve_*`, and retired
+`/problem-statement` entries are commented out (kept for restorability), not deleted. `/report`
+was retired as a slash command (KM-711) — report generation is the right-side button only.
 
 **FE behavior:** the `/` slash menu surfaces **`/help` only**. **Report is a right-side button, not
 a slash command** (it fires only when an analysis is finished — saves tokens).