Update framing: SpeckDL is the narrow waist humans and AI can work in

- Replace 'AI-generated, human-owned' with 'Two-Species Collaboration'
- Add 'Compiles to Wasm' as a distinct philosophy point
- README: new 'Chain of Custody for Intent' section
- Landing: updated hero tagline and philosophy cards
- SpeckDL compiles directly to Wasm through deterministic pipeline

Human intent is encoded in SpeckDL because it is judgeable by a person.
SpeckDL is useful for agentic work because it is easy for AI to write and reason about.

landing/index.html

@@ -195,7 +195,7 @@
 <header class="hero">
   <div class="hero-content">
     <h1>Speckl</h1>
-    <p class="hero-tagline">Spec-first development with dark provenance.<br>Write what your system should do. Prove it. Ship with full traceability.</p>
+    <p class="hero-tagline">Where humans and AI collaborate in the same language.<br>Spec-first development with dark provenance. Write what your system should do. Prove it. Ship with full traceability.</p>
     <div class="hero-cta">
       <a href="https://codeberg.org/sscoble/speckl" class="btn btn-primary">Source Code</a>
       <a href="https://codeberg.org/sscoble/speckl/src/branch/main/docs/whitepapers/dark-provenance.md" class="btn btn-secondary">Read the Whitepaper</a>
@@ -264,8 +264,12 @@
       <p>If Speck→WASM compilation preserves semantics, human review at the spec boundary satisfies assurance requirements.</p>
     </div>
     <div class="philosophy-item">
-      <h3>AI-Generated, Human-Owned</h3>
-      <p>Agents generate code. Humans own specifications. The chain of custody for intent stays intact.</p>
+      <h3>Two-Species Collaboration</h3>
+      <p>SpeckDL is the narrow waist both species can work in. Human-judgeable and AI-writable. Intent is encoded in the spec because humans can verify it; agents can draft and iterate at machine speed.</p>
+    </div>
+    <div class="philosophy-item">
+      <h3>Compiles to Wasm</h3>
+      <p>SpeckDL compiles directly to Wasm through a deterministic pipeline. The compiler is the enforcement point: if it compiles, the binary is faithful to the spec by construction.</p>
     </div>
   </div>
 </section>