Gemini: count the App's per-line tables in the page budget

Found in M3 while checking floors with the radio on: a windowed page left
1.5 to 3 KB less than the 40 KB steady floor (Q86), radio or not. The
budget counted TextBuffer's index (8 B/line) but not the App's tables,
which also grew by doubling. Now 16 B/line, and the App sizes them
exactly. The FAQ (1051 lines, windowed): 38.5 -> 39.6 KB after, radio
asleep; 37.1 -> 39.0 KB with the radio listening.

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

src/apps/gemini_app.cpp

@@ -103,8 +103,11 @@ void GeminiApp::show(GeminiPage&& page) {
 }
 
 void GeminiApp::analyse() {
-    types_.clear();
-    links_.clear();
+    // Sized exactly: the Service budgeted these bytes per line (kBytesPerLine), growth by
+    // doubling would take up to twice that.
+    std::vector<uint8_t>().swap(types_);
+    std::vector<uint32_t>().swap(links_);
+    types_.reserve(page_.text.lineCount());
     // A window may start inside a preformatted block: the index says (bit 31).
     size_t entry = page_.windowStart / GeminiService::kIndexEvery;
     bool pre = page_.windowed && entry < page_.lineIndex.size() && (page_.lineIndex[entry] & 0x80000000u);
@@ -114,6 +117,7 @@ void GeminiApp::analyse() {
         types_.push_back(static_cast<uint8_t>(t));
         if (t == LineType::Link) links_.push_back(i);
     }
+    links_.shrink_to_fit();
     layoutDirty_ = true;
     requestRedraw();
 }