feat(studio): plain-language ask bar + collapsible filter + AI search (v0.32.0)

Three changes against the user feedback "der text ist zu
zerhackt, die filter-leiste nimmt zu viel sicht weg, llm-suche
wenn das geht":

1. Today-Hero copy rewritten in flowing prose. The fallback
   story drops the code-fence templates ("`mcp.<server>.<tool>`")
   and reads as a single arc per language. Same trust model,
   gentler register.

2. Filter row collapses behind a single `_FilterButton` with a
   "Filter · N active" count badge. Status / Source / Installed
   chips now live inside `_FilterDialog` — invisible until the
   operator wants them, recovers a full row of viewport. The
   category strip stays inline because category is the most
   common cut and benefits from being one click away.

3. New `_AskBar` replaces the old single-line `_SearchField`:

   - Multi-line input (1-4 lines auto-grow) so questions don't
     overflow horizontally.
   - Cmd+Enter / Ctrl+Enter submits; bare Enter inserts a
     newline so the operator can write multi-line questions
     naturally.
   - Heuristic question detector (ends in `?` or ≥4 words)
     routes the submit to the System-AI's askAi RPC instead of
     the substring search. Live keystrokes still keyword-search
     for short queries; question-shaped input holds the grid
     steady until submit so the visible result set doesn't
     wipe with every space.
   - The LLM is asked for a strict-JSON ranking of up to 5
     modules with a one-phrase reason each. Unknown module
     names are dropped silently — operators must not see
     hallucinated entries.
   - The new `_AiAnswerCard` renders the LLM's answer plus the
     ranked match list above the grid; the grid filters to
     just those names so the answer and the visible cards
     stay coherent. Clearing the question collapses everything
     back.
   - Falls back to plain keyword search when System AI is off
     (with an explanatory hint instead of the AI hint).

The AI path uses the System-AI the operator already configured
in Settings; same privacy mode, same audit-log trail. Nothing
new leaves the hub.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/l10n/app_en.arb

@@ -104,6 +104,24 @@
   "channelsDisableAutostart": "Disable autostart",
 
   "storeSearchHint": "Search modules — name, tagline, tag, capability…",
+  "storeAskHint": "What do you need? Try \"a module that reads tabular data\" or just type a keyword.",
+  "storeAskSubmit": "Search",
+  "storeAskAi": "Ask the AI",
+  "storeAskClear": "Clear question",
+  "storeAskAiThinking": "Looking through modules…",
+  "storeAskAiUnavailable": "Configure a System AI in Settings to ask questions in plain language.",
+  "storeAskNoMatches": "No matches yet — refine the question or browse the grid below.",
+  "storeAskAnswerLabel": "AI suggestion",
+  "storeAskAnswerWhy": "Why this matches",
+  "storeAskMatchPill": "match",
+  "storeFilterLabel": "Filter",
+  "storeFilterActiveCount": "{n} active",
+  "@storeFilterActiveCount": { "placeholders": { "n": { "type": "int" } } },
+  "storeFilterReset": "Reset filters",
+  "storeFilterApply": "Done",
+  "storeFilterStatusGroup": "Status",
+  "storeFilterSourceGroup": "Source",
+  "storeFilterInstalledGroup": "Show only installed",
   "storeFeatured": "FEATURED",
   "storeFeaturedHint": "curated picks · click for details",
   "storeNoMatches": "No matches",