Notes: edit a text file of any size (#47)

The editor held the whole note in memory and stopped at 16 KB. It now keeps
a window of the file around the cursor, and the rest on the card as a list
of pieces (notes::NoteDocument). Memory with a note open is what it was.

Up to 64 KB a save rewrites the file, as before. Above, the five-second
save appends what changed to <note>.edit, and the file is rewritten on
leaving the note, with a progress bar. After a power cut, opening the note
picks the edit up where it was saved; a rewrite cut short is finished or
dropped, never half applied.

Also: Ctrl with Fn+Up/Down go to the start and end of the note; the
consoles' `key` command takes ctrl-, alt- and shift-; the Storage App's
`e` no longer refuses a big file.

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

src/main.cpp

@@ -10,6 +10,7 @@
 #include "app_manager.h"
 #include "png_rgb332.h"
 #include "apps/demo_app.h"
+#include "apps/note_editor.h"
 #include "apps/shell_app.h"
 #include "apps/gemini_app.h"
 #include "apps/gnss_app.h"
@@ -220,6 +221,8 @@ void setup() {
     apps->registerApp({"shell", "Shell", false, new ShellApp(shellRun, shellProbe, shellList, shellCount, helpText(), *apps)});
     // Leaving the foreground App makes it save: a note being typed, when the device is powered off.
     power->beforePowerOff = []() { apps->home(); };
+    // A long note being rewritten (issue #47): the editor waits for the card, so it draws from there.
+    NoteEditor::onProgress = [](const std::string& name, int percent) { screen.renderUpdate("Saving", name, percent); };
     apps->registerApp({"system", "System", false,
                        new SystemApp(*wifi, *battery, *storageService, *radioService, *gnssService, nvs)});
     apps->registerApp({"settings", "Settings", false,
@@ -653,7 +656,7 @@ static const char* const kHelp =
     "gnss status | gnss restart | gnss track start|stop | gnss nmea on|off | gnss send <sentence without $ and checksum>\n"
     "crash             the last crash: firmware, reason, task, backtrace\n"
     "coredump erase    forget the core dump in flash\n"
-    "key <name|char>   press a key: up down left right select back home del tab space help, or one character\n"
+    "key <name|char>   press a key: up down left right select back home del tab space help, or one character; ctrl- alt- shift- before it (key ctrl-down)\n"
     "wifi status | wifi add <ssid><TAB><password>\n"
     "wifi ip <ssid> dhcp | wifi ip <ssid> <address>/<prefix> [gateway]   a Saved Network's IP setting\n"
     "wifi dns <a> [b] | wifi dns always on|off | wifi ntp <a> [b]   DNS and NTP servers\n"
@@ -1026,12 +1029,23 @@ static void runCommand(String line, bool fromSerial = false) {
             bus.publish(Event::withText(EventType::Notification, ("Burst " + String(i)).c_str(), 0));
     if (line.startsWith("key ")) {  // key up|down|left|right|select|back|home|del|tab
         String k = line.substring(4);
+        // ctrl- alt- shift- before the name, in any order: `key ctrl-down`, `key alt-up`, `key ctrl-b`.
+        bool ctrl = false, alt = false, shift = false;
+        for (bool more = true; more;) {
+            more = false;
+            if (k.startsWith("ctrl-") && k.length() > 5) ctrl = more = true, k = k.substring(5);
+            if (k.startsWith("alt-") && k.length() > 4) alt = more = true, k = k.substring(4);
+            if (k.startsWith("shift-") && k.length() > 6) shift = more = true, k = k.substring(6);
+        }
         Key key = k == "up" ? Key::Up : k == "down" ? Key::Down : k == "left" ? Key::Left
                 : k == "right" ? Key::Right : k == "back" ? Key::Back : k == "home" ? Key::Home
                 : k == "del" ? Key::Delete : k == "tab" ? Key::Tab : k == "help" ? Key::Help : Key::Select;
         KeyEvent ev = k == "space"                       ? KeyEvent::character(' ')
                       : k.length() == 1 && k[0] > ' ' ? KeyEvent::character((unsigned char)k[0])
                                                       : KeyEvent::of(key);
+        ev.ctrl = ctrl;
+        ev.alt = alt;
+        ev.shift = shift;
         if (!power->onKey(millis())) apps->handleKey(ev);
     }
     if (line.startsWith("wifi add ")) {  // wifi add <ssid>\t<password>: credentials never touch the repo