fix(hello-world): name typo corrections, introduce Pi, and drop the Intro's doubled punctuation

challenges/hello-world/intro.md

@@ -1,5 +1,5 @@
-Meet Pi, your AI guide. Ask it to read the welcome note, `welcome.txt`, and
-say hello. Then ask it to make a small text file, `hello.txt`, that says
-`Hello, world!`. No terminal experience needed.
+Meet Pi, your AI guide. No terminal experience needed. Ask it to read the
+welcome note, `welcome.txt`, and say hello. Then ask it to make a small text
+file, `hello.txt`, that says **Hello, world!**
 
 You'll practice giving an agent a clear instruction and checking its work.

challenges/hello-world/skills/start-challenge/SKILL.md

@@ -8,8 +8,13 @@ description: Guide a participant through the Hello, World! booth challenge. Use
 Keep the tone warm and beginner-friendly. Work in the current workspace, not
 the installed package directory.
 
+Open your first message with "I'm Pi, your guide." Use that name, not a
+generic assistant title.
+
 1. Invite the participant to ask you to read `welcome.txt` and say hello. When
-   they do, read the file and greet them, then report step `greet`.
+   they do, read the file and greet them, then report step `greet`. If they
+   misname a file, say which one you'll use, for example "I think you meant
+   `welcome.txt`", before you read it.
 2. Invite them to ask you to make a file. When they do, create `hello.txt` in
    the workspace containing `Hello, world!`. Read it back to verify. If the
    file already exists, read it first and correct it if it doesn't contain

test/hello-world.test.mjs

@@ -60,6 +60,21 @@ test('skill names every step the manifest declares', async () => {
   }
 })
 
+test('skill has Pi introduce itself and name a corrected file name', async () => {
+  const skill = await readFile(path.join(challengeDirectory, 'skills/start-challenge/SKILL.md'), 'utf8')
+
+  assert.ok(skill.includes("I'm Pi, your guide."), 'skill never has Pi introduce itself')
+  assert.ok(skill.includes('I think you meant'), 'skill never has Pi name a corrected file name')
+})
+
+test('intro has no doubled punctuation once the station strips its markup', async () => {
+  const intro = await readFile(path.join(challengeDirectory, 'intro.md'), 'utf8')
+
+  const rendered = intro.replaceAll(/[`*]/g, '')
+
+  assert.doesNotMatch(rendered, /[!?.]\./)
+})
+
 test('setup seeds welcome.txt in the workspace', async (context) => {
   const cwd = await makeDirectory(context)
   const workspace = await makeDirectory(context)