Scott/follow up fixes

[sagrimson]

Overview

Improves the follow-up question flow and related queries experience in DataWeaver. Previously, broad/exploratory queries triggered a follow-up disambiguation step instead of returning data directly, follow-up context (the user's original question and selected option) was lost between turns, and multi-place queries could emit multiple conflicting follow-ups. This PR restructures how follow-up context is passed through the pipeline, tightens the data discovery skill to prefer returning data over asking clarifying questions, consolidates per-place follow-ups into a single synthesized message, adds related query suggestions to card footers, strips dead hyperlinks for variables with no data, and introduces a shuffled pool of example prompts.

Changes Made

• Structured follow-up context: Introduced a FollowUpContext type that chains the original query and each follow-up Q&A pair, passing it from the client store through the API route into both parseQuery and runToolLoop so Gemini has full conversation history when resolving follow-ups.
• Follow-up promoted to top-level stream event: Added a dedicated follow_up stream event type. Follow-ups are no longer embedded inside per-place QueryResult objects — they're collected across all places in the loop, merged into a single disambiguation message, and emitted once at the end of the stream. This fixes the issue of multiple follow-ups appearing for multi-place queries.
• Post-loop follow-up synthesis: The API route now accumulates disambiguation signals from each place iteration and synthesizes at most one merged follow-up (combining summaries and deduplicating options). A generic fallback follow-up is emitted if no results and no disambiguation signals were produced.
• nodeSetFollowUp store action: Added a new store action to write the synthesized follow-up directly onto the HistoryNode, decoupling it from query results. PageHome now reads latestNode.followUp directly instead of scanning through results.
• Data discovery skill rewrite: Rewrote data_discovery.md to only use followUp as a last-resort fallback (no data found / unintelligible / adversarial query) rather than a disambiguation step for broad queries. Clarified that followUp is an orchestrator signal, not user-facing output. Added rules for data verification, DCID accuracy, place passing, and the new relatedQueries output field.
• Related queries on cards: Changed relatedQuery (single string) → relatedQueries (string array) across CardChart, CardText, shape props, helpers, and sync_store. Card footers now render multiple related-query buttons in a vertical stack.
• Card footer layout: Updated footer.module.scss to use column flexbox with gap for stacked related-query buttons.
• Strip no-data hyperlinks: render_result_html.ts now identifies which variables actually have time-series data and converts #fetch= markdown links for empty variables into plain text — both in the table rows and in the introduction/coverage/insights prose.
• Safety skill relaxed: Modified the safety classifier to only block genuinely malicious/jailbreak queries; off-topic or nonsensical queries are now allowed through and handled downstream by data discovery.
• Follow-up dismissal persisted to store: Replaced local dismissedNodeId state in PageHome with a nodeDismissFollowUp store action that removes the follow-up from the node, preventing reappearance on re-renders.
• Node removal on follow-up dismissal: When a follow-up is dismissed, the associated history node is cleaned up.
• Example prompts extracted & shuffled: Moved hardcoded example prompts from Intro into a shared configs/example_prompts.ts pool of 20 prompts. The page server component shuffles and slices 4 at render time. The follow-up component also pulls from this pool as a fallback when the API returns no options.
• Place resolution defaults to Earth: When no explicit place is found, the route now defaults to "Earth" instead of using the raw query string as a place, and strips follow-up options so the model asks the user to specify a location.
• Parse query improvements: Updated parse_query.md and parse_query.ts to extract places from the full follow-up conversation context and to be more conservative about marking queries as follow-ups when they contain explicit places/topics.
• Simplified per-place result flow: Removed follow-up handling from the per-place card registration path in query_provider — results now always register cards, and follow-ups arrive separately via the new stream event.

[gemini-code-assist]

Code Review

This pull request introduces a structured followUpContext to track conversation history (original query and Q&A chain) for follow-up queries, replacing simple query string concatenation. It also defaults the target place to "Earth" when no explicit place is provided, stripping follow-up options in this scenario to prompt the user for a location. A critical issue was identified in route.ts where the resolved places array is not assigned back to parsed.places after fallback logic, which would prevent the default place from propagating to the client and downstream history nodes.