Add gather-hardware-info.sh — auto-detects most report fields

Reads /proc, /sys, and common CLI tools (lscpu, lsblk, lspci, lsusb) to
print a YAML block matching data/schema.json: device model (DMI on x86,
/proc/device-tree/model on ARM SBCs), form factor (best-effort — battery
presence, DMI chassis type, device-tree presence), CPU, RAM, root storage
type/size, WiFi chip (PCI, then USB, then falls back to driver name rather
than guessing wrong), ethernet. Fields it can't detect (archy_version,
install_method, status) are left as clearly-marked TODOs rather than
guessed. Local-only — no network calls, changes nothing.

Tested for real on this box (a QEMU VM): correctly identified it as a VM,
correctly fell back to "other" with a TODO for form_factor rather than
guessing, output validated as parseable YAML. Passes shellcheck clean.

Linked from the homepage, report.html, and CONTRIBUTING.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

site/index.html

@@ -14,6 +14,13 @@
     Tested Archipelago on your own hardware? <a href="report.html">Report it</a> —
     takes two minutes and helps the next person know what to expect before they buy or repurpose a machine.
   </p>
+  <p class="cta-secondary">
+    Not sure of your exact CPU/WiFi chip/etc.? Run
+    <a href="gather-hardware-info.sh">this script</a> on the machine you
+    tested — <code>bash gather-hardware-info.sh</code> — it prints most of
+    the fields for you, ready to paste into the form above. Local-only, no
+    network calls, <a href="gather-hardware-info.sh" target="_blank" rel="noopener">read it</a> before you run it like you should with any script.
+  </p>
 </header>
 
 <main>