Update libveritas and include examples

.github/workflows/snippets.yml

@@ -0,0 +1,64 @@
+name: Extract code snippets
+
+on:
+  push:
+    paths:
+      - "fabric/examples/**"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+jobs:
+  extract:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Extract snippets
+        run: |
+          cd fabric/examples
+          mkdir -p /tmp/snippets
+
+          for lang_file in \
+            rust/src/main.rs \
+            js/index.mjs \
+            go/main.go \
+            python/example.py \
+            kotlin/Example.kt \
+            swift/Example.swift; do
+
+            lang=$(dirname "$lang_file" | cut -d/ -f1)
+            mkdir -p "/tmp/snippets/$lang"
+            ./extract-snippets.sh "$lang_file" "/tmp/snippets/$lang"
+          done
+
+          # Create index
+          echo "# Code Snippets" > /tmp/snippets/index.md
+          echo "" >> /tmp/snippets/index.md
+          for lang in rust js go python kotlin swift; do
+            echo "## $lang" >> /tmp/snippets/index.md
+            for f in /tmp/snippets/$lang/*.txt; do
+              name=$(basename "$f" .txt)
+              echo "- [$name]($lang/$name.txt)" >> /tmp/snippets/index.md
+            done
+            echo "" >> /tmp/snippets/index.md
+          done
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: /tmp/snippets
+
+  deploy:
+    needs: extract
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

fabric/examples/extract-snippets.sh

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+#!/usr/bin/env bash
+set -eo pipefail
+#
+# Extract code snippets from example files.
+#
+# Snippets are delimited by <doc:name> and </doc:name> tags.
+# Output: one file per snippet in the output directory.
+#
+# Usage:
+#   ./extract-snippets.sh rust/src/main.rs snippets/rust
+#   ./extract-snippets.sh js/index.mjs snippets/js
+#
+
+INPUT="${1:?Usage: extract-snippets.sh <input-file> <output-dir>}"
+OUTDIR="${2:?Usage: extract-snippets.sh <input-file> <output-dir>}"
+
+mkdir -p "$OUTDIR"
+
+# Detect language from file extension
+EXT="txt"
+
+# Extract each <doc:name> ... </doc:name> block
+current_tag=""
+current_file=""
+
+while IFS= read -r line; do
+    # Check for opening tag
+    if [[ "$line" =~ \<doc:([a-zA-Z0-9_-]+)\> ]]; then
+        current_tag="${BASH_REMATCH[1]}"
+        current_file="$OUTDIR/${current_tag}.${EXT}"
+        > "$current_file"  # truncate
+        continue
+    fi
+
+    # Check for closing tag
+    if [[ "$line" =~ \</doc: ]]; then
+        if [ -n "$current_file" ]; then
+            echo "  extracted: $current_tag -> $current_file"
+        fi
+        current_tag=""
+        current_file=""
+        continue
+    fi
+
+    # Write line to current snippet (strip common leading whitespace)
+    if [ -n "$current_file" ]; then
+        echo "$line" >> "$current_file"
+    fi
+done < "$INPUT"
+
+# Clean up: strip common leading whitespace from each snippet
+for f in "$OUTDIR"/*."$EXT"; do
+    [ -f "$f" ] || continue
+    # Find minimum indentation (ignoring blank lines)
+    min_indent=$(sed -n '/[^ ]/{ s/^\( *\).*/\1/; p; }' "$f" | awk '{ print length }' | sort -n | head -1)
+    if [ -n "$min_indent" ] && [ "$min_indent" -gt 0 ]; then
+        if sed -i '' "s/^ \{1,$min_indent\}//" "$f" 2>/dev/null; then
+            : # macOS sed
+        else
+            sed -i "s/^ \{1,$min_indent\}//" "$f"  # Linux sed
+        fi
+    fi
+done
+
+echo "Done: $(ls "$OUTDIR"/*."$EXT" 2>/dev/null | wc -l | tr -d ' ') snippets extracted"

fabric/examples/go/go.mod

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+module example-go
+
+go 1.22
+
+require github.com/spacesprotocol/fabric-go v0.0.0-dev.20260401232107
+
+require (
+	github.com/spacesprotocol/libveritas-go v0.0.0-dev.20260401232107 // indirect
+	github.com/btcsuite/btcd/btcec/v2 v2.3.6 // indirect
+	github.com/btcsuite/btcd/chaincfg/chainhash v1.0.1 // indirect
+	github.com/decred/dcrd/crypto/blake256 v1.0.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+)