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/apps/storage_app.cpp

@@ -199,7 +199,7 @@ void StorageApp::onFinished(const FileOps::Status& s) {
 }
 
 void StorageApp::paste(bool replace) {
-    if (!clip_) return say("Nothing to paste: c copies, x cuts");
+    if (!clip_) return say("Nothing to paste: copy or cut something first");
     std::string name = baseName(clip_.path), why;
     if (cut_) {
         why = ops_.move(clip_.path, clip_.folder, joinPath(cwd_, name), replace);
@@ -273,6 +273,45 @@ void StorageApp::showDetails(const Item& item) {
     view_ = View::Details;
 }
 
+void StorageApp::help(std::vector<KeyHelp>& out) const {
+    switch (view_) {
+        case View::NoMemory: return;
+        case View::Maintenance: return maintenance_.help(out);
+        case View::Editor: return noteEditor_.help(out);
+        case View::Viewer: return viewer_.help(out);
+        case View::Details:
+            out.push_back({"; .", "scroll"});
+            out.push_back({"Enter", "back to the folder"});
+            return;
+        default: break;
+    }
+    if (dialog_) return help::dialog(out);
+    if (wantList_ || wait_ != Wait::None) return (void)out.push_back({"`", "stop the copy or the delete"});
+    if (view_ == View::Name) return help::textEntry(out, renaming_ ? "rename it" : "make the folder");
+    help::list(out, "open the folder or the file");
+    out.push_back({", /", "a page up, down"});
+    out.push_back({"c  x", "copy, cut"});
+    out.push_back({"v", "paste here"});
+    out.push_back({"r", "rename"});
+    out.push_back({"d  Del", "delete, after asking"});
+    out.push_back({"n", "a new folder"});
+    out.push_back({"i", "details: size, date, type"});
+    out.push_back({"s", "sort: name, date, size"});
+    out.push_back({"m", "Maintenance: clean-up, erase"});
+    out.push_back({"`", "the folder above"});
+}
+
+const char* StorageApp::helpTitle() const {
+    switch (view_) {
+        case View::Maintenance: return "Storage: maintenance";
+        case View::Editor: return "Storage: the editor";
+        case View::Viewer: return "Storage: a file";
+        case View::Details: return "Storage: details";
+        case View::Name: return "Storage: a name";
+        default: return nullptr;
+    }
+}
+
 bool StorageApp::onKey(const KeyEvent& e) {
     requestRedraw();
     if (view_ == View::NoMemory) return false;
@@ -434,7 +473,7 @@ bool StorageApp::onBrowseKey(const KeyEvent& e) {
     if (ch == 'c') {
         clip_ = item;
         cut_ = false;
-        say("v pastes a copy of " + name);
+        say("Copied " + name + ": paste it where you like");
         return true;
     }
     // Cut, rename and delete change the original: the rules of Q130 first.
@@ -446,7 +485,7 @@ bool StorageApp::onBrowseKey(const KeyEvent& e) {
     if (ch == 'x') {
         clip_ = item;
         cut_ = true;
-        say("v moves " + name + " here");
+        say("Cut " + name + ": paste it where it should go");
     } else if (ch == 'r') {
         target_ = item;
         renaming_ = true;
@@ -542,7 +581,6 @@ void StorageApp::drawBrowse(Canvas& c) {
     } else if (rows_.count() == 0) {
         c.setTextColor(theme::kMuted);
         c.drawString("Nothing in this folder.", 4, rows.y + 4);
-        c.drawString("n makes a folder, v pastes.", 4, rows.y + 4 + theme::kLineHeight);
     } else {
         int entries = static_cast<int>(list_.count());
         auto value = [&](int i) {
@@ -558,13 +596,13 @@ void StorageApp::drawBrowse(Canvas& c) {
             value);
     }
 
-    // Footer: a message for a few seconds, what v would paste, or the keys.
+    // Footer: a message for a few seconds, or what a paste would do. Never the keys (Fn+h).
     c.setFont(&fonts::small);
     bool showMessage = !message_.empty() && millis() - messageMs_ < kMessageMs;
     c.setTextColor(showMessage ? theme::kWarning : theme::kMuted);
-    std::string keys = "c x v:paste r:name d:del n:new i:info s:sort";
+    std::string keys;
     if ((wantList_ || wait_ == Wait::List) && millis() - waitSinceMs_ >= kQuietMs) keys = "Reading " + files::fitName(want_, 30) + "...";
-    else if (clip_) keys = std::string("v: ") + (cut_ ? "move " : "copy ") + files::fitName(baseName(clip_.path), 20) + " here";
+    else if (clip_) keys = std::string(cut_ ? "Cut: " : "Copied: ") + files::fitName(baseName(clip_.path), 28);
     c.drawString(showMessage ? message_.c_str() : keys.c_str(), 4, area.y + area.h - 9);
 }
 
@@ -589,8 +627,6 @@ void StorageApp::drawProgress(Canvas& c) {
         line = formatBytes(s.doneBytes) + " of " + formatBytes(s.totalBytes);
     }
     c.drawString(line.c_str(), box.x + 6, box.y + 31);
-    c.setFont(&fonts::small);
-    c.drawString("Back: cancel", box.x + 6, box.y + box.h - 10);
 }
 
 }  // namespace roro