feat(voice): add typed AI chat beside voice

Chat sits next to the mic in the command dock. Replies are silent and never
request the microphone; the first message connects with the selected provider
and runs the same map actions as voice through each provider's text API
(OpenAI OPENAI_CHAT_MODEL, Gemini GEMINI_CHAT_MODEL via generateContent, which
never starts Live). Only one mode runs at a time.

- Chat panel rendered by the voice control presenter: conversation, recent and
  quick-command suggestions, Up/Down history, attachments (map-layer
  references or small UTF-8 text files, sent only with the message)
- Chat and voice panels sit above the dock or dock into the right rail's
  column; minimized bars sit centred above the dock, and height animates on
  swaps
- A centred panel steps down to its bar for the Location and Visual Presets
  trays without moving focus, rests above an open tray, and docks right while
  expanded over one; it returns to the centre once the trays close
- Minimized voice previews the last sentence from each side; the empty Voice
  Preview suggests things to say
- Settings opened from chat keep chat's frame and show the shared AI provider
  and quick commands; voice Settings show Back to voice
- Closing chat ends a typed session; the voice panel's close turns voice off
- The dock widens its voice control for the chat button and restyles its
  wings, which show icons only at 900px and below; assistant panels share the
  left panels' glass, and Cyber keeps its own surfaces
- Server text-chat handlers with body, time and per-IP limits
  (GEV_RATELIMIT_*_CHAT_PER_MIN), documented in SECURITY.md; tests and all
  eleven locales

Co-authored-by: Darren Dignam <[email protected]>

server/providers/common/textInstructions.js

@@ -0,0 +1,31 @@
+import { realtimeDirectives } from '../openai/instructions.js';
+
+// Voice wording in the shared directives and its written form. A test checks
+// each phrase still occurs in the directives, so rewording one there fails
+// rather than leaking spoken wording into chat.
+export const TEXT_WORDING = Object.freeze([
+  ['without speaking first', 'without writing a preamble'],
+  ['before speaking', 'before confirming'],
+  ['may first say ONE sentence', 'may first write ONE sentence'],
+  ["speak the result's say line", "write the result's say line"],
+  ['on the voice card: speak a caveat', 'in the tool result: include a caveat'],
+  ['as you talk', 'as you write'],
+  ['you can read aloud', 'you can report'],
+]);
+
+// Shared-manual adaptation follows Darren Dignam's GEV COMMAND approach (#976).
+// Keep our Radio handoff and annotation outcome policies from the shared manual.
+export function textInstructions(annotationGuidance) {
+  return realtimeDirectives(annotationGuidance)
+    .map((line, index) => {
+      if (index === 0)
+        return "You are GEV Chat, a concise text assistant for a Cesium geospatial app called God's Eye View.";
+      if (index === 1)
+        return 'Have a natural written conversation. This is text-only chat; no microphone or generated audio is used.';
+      return TEXT_WORDING.reduce(
+        (text, [spoken, written]) => text.replace(spoken, written),
+        line,
+      );
+    })
+    .join('\n');
+}