Help: Fn+h lists the keys of the screen you're on, and no screen names its keys any more (#69)

Fn+h on any screen, text fields included, and ? outside Text Entry, open a
panel over the content area: the screen's own keys, then the ones that work
everywhere. Every App declares its keys for the state it is in (pages,
viewers, dialogs and text fields answer for themselves); the App manager
opens the panel and takes every key while it is open.

About 30 hint lines are gone, from every App. What stays on a screen is
state. The first-start Setup keeps its hints and teaches the key; a device
set up before gets one Toast, once. The guide and the FAQ open with it.
`key help` over the consoles.

476 host tests (8 new). Checked on the device with key help and screenshots:
the Launcher, all nine Apps and several of their states. 8.5 KB of flash and
40 bytes of static RAM. Decisions Q196 to Q203 in docs/milestones/U1.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/services/gemini_service.cpp

@@ -459,8 +459,7 @@ void GeminiService::openSaved(const std::string& path, GeminiPage& page) {
 
 // about:start (Q78, Q84): bookmarks, then Saved Pages by capsule, newest first, then defaults.
 void GeminiService::composeStart(GeminiPage& page) {
-    std::string doc = "# Gemini\nTab picks a link, Enter follows it, Back returns, g types an address. "
-                      "On a page: b bookmarks it, s saves it to read offline, S with the pages it links to.\n";
+    std::string doc = "# Gemini\nYour bookmarks and Saved Pages, then a few places to start.\n";
     std::string bookmarks;
     std::vector<SavedEntry> saved;
     bool card = storage_.runAndWait([&]() {