Add Proof of Human (PoH) credential documentation

.gitignore

@@ -8,3 +8,4 @@ images/docs/mini-apps/guidelines/do-dont/nav-component-dont.png
 mini-apps/guidelines/do-dont.mdx
 scripts/check-meta-images.js
 scripts/add-meta-images.js
+.idea/

docs.json

@@ -85,6 +85,7 @@
           {
             "group": "Credentials",
             "pages": [
+              "world-id/credentials/1",
               "world-id/credentials/9303",
               "world-id/credentials/11"
             ]

world-id/credentials/1.mdx

@@ -0,0 +1,92 @@
+---
+title: "Proof of Human (PoH)"
+icon: "eye"
+iconType: "duotone"
+description: "High assurance biometric credential captured by the Orb and used for uniqueness."
+"og:image": "https://docs.world.org/images/docs/docs-meta.png"
+"twitter:image": "https://docs.world.org/images/docs/docs-meta.png"
+---
+
+import { CredentialHero } from "/snippets/credential-hero.jsx";
+
+<CredentialHero
+  title="Proof of Human"
+  description="A high-assurance biometric credential using the Orb for uniqueness."
+  image="/images/docs/id/issuers/1/thumbnail.png"
+  bgColor="#6b5320"
+  issuerName="World Foundation"
+  issuerHref="https://world.org/"
+  issuerVerified={true}
+  status="active"
+  id={1}
+  sybilResistance={true}
+  sybilResistanceDescription="Each human can only have one PoH credential."
+  validityPeriod="3 years"
+  sourceCodeHref="coming-soon"
+/>
+
+## Introduction
+
+The Proof of Human (PoH) Credential is the highest-assurance credential issued under World ID. Enrollment is a two-step process: the user first obtains an Orb credential by completing an Orb capture process, which proves they are a live human. They then exchange that Orb credential at the **PoH Issuer Service** with a PoH credential which confirms uniqueness.
+
+## Use Cases
+
+Use the PoH Credential when you need a strong guarantee that you are interacting with a unique, live human. It is the right choice for:
+
+- **Sybil resistance**: enforcing one account per human for airdrops, voting, rewards, or rate limiting.
+- **High-assurance authentication**: gating sensitive actions where you need biometric confidence that you're interacting with the correct, unique human.
+- **Proof of personhood**: distinguishing humans from bots, agents, and synthetic identities.
+
+## Credential Structure
+
+This credential implements the following attributes beyond the defaults in the [Credential](https://docs.rs/world-id-primitives/latest/world_id_primitives/credential/struct.Credential.html).
+
+<table>
+  <thead>
+    <tr>
+      <th className="whitespace-nowrap">Attribute</th>
+      <th>Description</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td className="whitespace-nowrap">
+        <code>genesis_issued_at</code>
+      </td>
+      <td>The Unix timestamp of the user's first PoH credential. Remains constant across credential renewals.</td>
+    </tr>
+    <tr>
+      <td className="whitespace-nowrap">
+        <code>expires_at</code>
+      </td>
+      <td>Unix timestamp when the credential expires. This is currently three years after the most recent issuance.</td>
+    </tr>
+    <tr>
+      <td className="whitespace-nowrap">
+        <code>associated_data_hash</code>
+      </td>
+      <td>
+        The PoH credential has no associated data, so this field is always{" "}
+        <code>FieldElement::ZERO</code>.
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+In addition, the credential implements the following claim:
+
+### Claim 0 - Orb Credential Commitment
+
+A commitment that binds the PoH credential to the Orb credential the user presented at issuance. This allows the PoH Issuer to attest that the credential was minted from a valid Orb verification without revealing the underlying Orb credential to relying parties.
+
+| Source                  | Value                                                                                            |
+| ----------------------- | ------------------------------------------------------------------------------------------------ |
+| Orb credential          | `H(hashes.json)` — the hash signed by the Orb during enrollment.                                 |
+
+## Credential Renewal
+
+Users can renew their PoH credential to extend its validity as long as the Orb capture is deemed fresh by the issuer. Each renewal updates the credential with `expires_at = now + 3 years` while `genesis_issued_at` remains constant.
+
+## Technical Reference
+
+For issuer endpoints and implementation-specific details, see the [PoH Issuer reference](/world-id/reference/poh-issuer).