fix(tools): name case-sensitive arg_names + 100-col grid in configure_popup_modal_layer popup_config description

[romer8]

Summary

Two distinct LLM-routing bugs surfaced in turn-2 testing of the popup-modal MCP surface, both caused by missing anchoring text in the `configure_popup_modal_layer`'s `popup_config` field description. One commit, two CRITICAL clauses added.

Root causes (full /ce-debug 2026-05-21 turn 2)

Bug A — arg-name case mismatch

User prompt: "embed the GeoGLOWS Forecast Plot plugin with River ID = ${feature.comid}"

`list_intake_plugins` (prior turn) returned:
```json
{"source": "geoglows_forecast_plot", "arg_names": ["river_ID"]}
```

LLM emitted:
```json
"args_string": "{\"river_id\": \"${feature.comid}\"}"
```

Lowercase `river_id` vs canonical `river_ID`. The LLM normalized the user's natural-language label and ignored the authoritative `arg_names`. At runtime, plugin `run()` looked up `river_ID` → undefined → no data fetched. Edit Visualization modal's "River ID" form input (bound to key `river_ID`) rendered empty.

Bug B — popup gridItem too small (Bootstrap 12-col default)

User prompt said "filling the popup grid." LLM emitted `w=12, h=12` — Bootstrap convention. But the popup uses tethysdash's `DashboardLayout` with `colCount=100` (`DashboardLayout.js:30`). React UI's `buildNewGridItem` defaults to `w=20, h=20`. The LLM's `w=12` rendered the tile at ~12% of popup width — visibly too small (geoglows_forecast_plot placeholder text wrapped vertically in a narrow column).

Fix

Extend the `popup_config` field description with two CRITICAL clauses anchoring:

1. gridItems[].args keys to the case-sensitive `arg_names` from `list_intake_plugins` / `list_available_visualizations` (with explicit anti-pattern call-out: "if arg_names contains river_ID, the key MUST be river_ID — NOT river_id, River ID, or riverId").

2. gridItems[].position fields (x, y, w, h) to the popup's 100-column react-grid-layout, with explicit negation of Bootstrap's 12-col convention: "the SAME grid system as the main tethysdash dashboard — NOT Bootstrap's 12-column grid."

Tests

2 new in `TestPopupConfigFieldDescription`:

• `test_field_description_names_args_case_sensitivity` — asserts "case-sensitive" + "arg_names" appear
• `test_field_description_names_popup_grid_col_count` — asserts "100-column" present + Bootstrap 12-col explicitly negated

Full suite: 937 passed (935 baseline + 2 new).

Escalation path

If a subsequent LLM still gets either case or cols wrong after this tightening, the next step is server-side case-insensitive arg-name normalization (Option B from the /ce-debug session) — fetch the source's `arg_names` from `TETHYSDASH_BASE_URL` and case-fold-match the keys server-side. That adds a network call per `configure_popup_modal_layer` invocation; deferred until we observe description-tightening fail.

Workspace memory `feedback_proactive_over_reactive_llm_routing.md` notes: "pattern-matching against open-vocabulary model output is a losing fight." Description tightening has worked for PR #11 (popup_options aliases) and partially for the bigger PRIORITY-clause work; it's our cheapest tool but not infinitely reliable. We measure first, escalate second.

Manual smoke after merge

Restart MCP server. Re-run the turn-2 prompt:

Enable the Custom Popup Modal on the China Flowlines layer with the title template "GeoGLOWS Forecast — ${feature.comid}". Inside the popup, embed the GeoGLOWS Forecast Plot plugin with River ID = ${feature.comid}, filling the popup grid.

Expected:

• `args_string` contains `"river_ID"` (capital ID), not `"river_id"`
• gridItem dims close to `w=100, h=40-60` (fills popup width)
• At runtime: popup opens with title substituted, GeoGLOWS Forecast Plot fetches with the real comid value
• Edit Visualization modal: "River ID" field populated with `${feature.comid}`