Keys: one table file for the device's help panel and the website's key tables (#72)

Every screen's keys are constant tables in lib/core/src/app_keys.h (52 of
them, each under an `// id: Title` comment). An App's help() picks the table
of the state it is in. site/tools/gen_dev_docs.py reads the same file and
writes site/data/keys.toml; the `keys` shortcode shows a screen's tables on
its guide page, and /guide/keys/ shows all of them.

The Site job fails when the data file is out of date or a page asks for a
table that doesn't exist, and now also runs when app_keys.h changes. A key
added to an App shows up on the website without anyone editing a page.

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

src/apps/wifi_tools_app.cpp

@@ -1,3 +1,4 @@
+#include "app_keys.h"
 #include "wifi_tools_app.h"
 
 #include <M5Cardputer.h>
@@ -155,17 +156,10 @@ void WifiToolsApp::draw(Canvas& c) {
 
 void WifiToolsApp::help(std::vector<KeyHelp>& out) const {
     switch (view_) {
-        case View::Menu: help::list(out); break;
-        case View::Networks:
-            help::list(out, "track its signal");
-            out.push_back({"s", "sort: signal, channel, name"});
-            out.push_back({"o", "open networks only"});
-            out.push_back({"h", "hide the hidden ones"});
-            out.push_back({"w", "strong ones only"});
-            out.push_back({"l", "log the scans to the card"});
-            break;
-        case View::Channels: break;
-        case View::Tracker: out.push_back({"m", "clicks on or off"}); break;
+        case View::Menu: keys::add(out, keys::kWifiTools); break;
+        case View::Networks: keys::add(out, keys::kWifiNetworks); break;
+        case View::Channels: break;  // nothing but the keys that work everywhere
+        case View::Tracker: keys::add(out, keys::kWifiTracker); break;
     }
 }