Add piped input support and documentation for cf picker

- Support piped input: cat file.txt | cf | cf
- Write picker UI to stderr when stdout is piped
- Use /dev/tty for keyboard input independent of stdin
- Add select() for non-blocking escape sequence detection
- Document cf in CLI reference and Getting Started

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/cmdforge/web/docs_content.py

@@ -35,7 +35,10 @@ cmdforge create   # CLI wizard
 cmdforge registry install official/summarize
 
 # Use it!
-cat article.txt | summarize</code></pre>
+cat article.txt | summarize
+
+# Or use the interactive picker to browse and run tools
+cf</code></pre>
 
 <div class="bg-cyan-50 border-l-4 border-cyan-500 p-4 my-4">
     <p class="font-semibold text-cyan-800">Two Ways to Build</p>
@@ -3949,6 +3952,36 @@ cat file.txt | summarize --provider mock</code></pre>
     </tbody>
 </table>
 
+<h2 id="interactive-picker">Interactive Tool Picker (cf)</h2>
+
+<p>The <code>cf</code> command provides a fast, fuzzy-search picker for running tools interactively.
+Instead of remembering exact tool names, just type a few characters to filter and select.</p>
+
+<pre><code class="language-bash"># Launch the picker
+cf
+
+# Pipe input through the picker
+cat document.txt | cf
+
+# Chain pickers for interactive pipelines
+cf | cf | cf</code></pre>
+
+<p><strong>Controls:</strong></p>
+<ul>
+    <li><strong>Type</strong> - Fuzzy filter tools by name or description</li>
+    <li><strong>↑/↓</strong> - Navigate the list</li>
+    <li><strong>Enter</strong> - Run the selected tool</li>
+    <li><strong>Tab</strong> - Configure arguments before running (if tool has arguments)</li>
+    <li><strong>Esc</strong> - Cancel</li>
+</ul>
+
+<div class="bg-cyan-50 border-l-4 border-cyan-500 p-4 my-4">
+    <p class="font-semibold text-cyan-800">Interactive Pipelines</p>
+    <p class="text-cyan-700">Chain <code>cf</code> commands to build pipelines on the fly:
+    <code>cat data.txt | cf | cf</code> lets you pick a tool, then pick another tool to process its output.
+    The picker UI is shown on stderr so it doesn't interfere with piped data.</p>
+</div>
+
 <h2 id="registry-commands">Registry Commands</h2>
 
 <table class="w-full my-4">
@@ -4166,6 +4199,7 @@ cat file.txt | summarize --provider mock</code></pre>
 """,
         "headings": [
             ("tool-commands", "Tool Commands"),
+            ("interactive-picker", "Interactive Tool Picker (cf)"),
             ("registry-commands", "Registry Commands"),
             ("collection-commands", "Collection Commands"),
             ("provider-commands", "Provider Commands"),