refactor!: claim references are claim:TAG

lode is renamed paperclaim. A claim reference is claim:TAG or
claim:host/TAG and a pin claim:TAG@hex6 (claimRef and claimPin in
common.schema.json, spec/18 §18.4, spec/02, spec/20); the eight-character
tags do not change. A project names its claim namespace as
claims.paperclaim, and the main example's targeted receipts take the
scope targeted:paperclaim. No old prefix or name is accepted.

paperspec build regenerated the fixtures and vectors: the claim link's and
the symbol's record IDs, the layer receipt, project.json, the two targeted
receipts and Ben's spot-check, the QA report, the inclusion proof, the log's
checkpoint and tiles, and the signature, spot-check, VRF and checkpoint
vectors. The walkthrough and examples quote the new receipt IDs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SarHTuHhV9cS85XWy2NrLJ

schemas/common.schema.json

@@ -73,12 +73,12 @@
     },
     "claimRef": {
       "type": "string",
-      "pattern": "^lode:([a-z0-9.-]+\\.[a-z]{2,}/)?[0-9A-HJKMNP-TV-Z]{8}$",
-      "description": "A claim in a lode store: lode:TAG, or lode:host/TAG for another store, TAG eight Crockford base32 capitals (spec/18 §18.4)."
+      "pattern": "^claim:([a-z0-9.-]+\\.[a-z]{2,}/)?[0-9A-HJKMNP-TV-Z]{8}$",
+      "description": "A claim in a paperclaim store: claim:TAG, or claim:host/TAG for another store, TAG eight Crockford base32 capitals (spec/18 §18.4)."
     },
     "claimPin": {
       "type": "string",
-      "pattern": "^lode:([a-z0-9.-]+\\.[a-z]{2,}/)?[0-9A-HJKMNP-TV-Z]{8}@[0-9a-f]{6}$",
+      "pattern": "^claim:([a-z0-9.-]+\\.[a-z]{2,}/)?[0-9A-HJKMNP-TV-Z]{8}@[0-9a-f]{6}$",
       "description": "A claim pinned to its statement: the claim's reference, @ and the first six hex digits of its statement hash (spec/18 §18.4)."
     },
     "mathForm": {

schemas/project.schema.json

@@ -186,13 +186,13 @@
     "claims": {
       "type": "object",
       "properties": {
-        "lode": {
+        "paperclaim": {
           "type": "string",
           "minLength": 1
         }
       },
       "required": [
-        "lode"
+        "paperclaim"
       ],
       "additionalProperties": false
     },