feat: rename to issue-core and add task ingestion endpoint

Renames the package, distribution, CLI alias, Makefile targets, and
working directory from issue-facade to issue-core, signalling its
role as the authoritative task lifecycle manager for the Coulomb org
(peer to activity-core, rules-core, project-core).

Adds POST /issues/ ingestion endpoint for activity-core's IssueSink,
under a new optional [api] extra. The endpoint is served by `issue
serve`, authenticates via the ISSUE_CORE_API_KEY env var (Bearer or
X-API-Key header), and routes the TaskSpec payload to the configured
default backend with full traceability metadata embedded in
sync_metadata.

- T01: Python package issue_tracker -> issue_core, dir rename
- T02: registered in state hub under custodian domain
- T03: INTENT.md (what it is, what it isn't, how it fits)
- T04: SCOPE.md (in/out-of-scope, integration boundaries)
- T05: POST /issues/ via FastAPI + Uvicorn, 9 unit tests
- T06: docs/nats-task-ingestion.md design stub

Closes ISSC-WP-0001.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.capability/integrate.sh

@@ -1,14 +1,14 @@
 #!/bin/bash
-# Integration script for issue-facade capability
+# Integration script for issue-core capability
 # This script helps the main project discover and integrate the capability
 
 set -e
 
-CAPABILITY_NAME="issue-facade"
+CAPABILITY_NAME="issue-core"
 CAPABILITY_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 PROJECT_ROOT="${PROJECT_ROOT:-$(cd "$CAPABILITY_DIR/../.." && pwd)}"
 
-echo "🔧 Issue Facade Capability Integration"
+echo "🔧 Issue Core Capability Integration"
 echo "   Capability: $CAPABILITY_DIR"
 echo "   Project:    $PROJECT_ROOT"
 echo ""
@@ -90,7 +90,7 @@ case $choice in
         echo "📝 Adding to Claude Code context..."
         mkdir -p "$PROJECT_ROOT/.claude/capabilities"
         cp "$CAPABILITY_DIR/.capability/agent-context.md" \
-           "$PROJECT_ROOT/.claude/capabilities/issue-facade.md"
+           "$PROJECT_ROOT/.claude/capabilities/issue-core.md"
 
         # Create or update context file
         CONTEXT_FILE="$PROJECT_ROOT/.claude/context/capabilities.md"
@@ -102,10 +102,10 @@ case $choice in
 
 This project uses specialized capabilities. Always check for existing capabilities before implementing similar functionality.
 
-## Issue Tracking: issue-facade
+## Issue Tracking: issue-core
 
-**Location:** `capabilities/issue-facade/`
-**Documentation:** `.claude/capabilities/issue-facade.md`
+**Location:** `capabilities/issue-core/`
+**Documentation:** `.claude/capabilities/issue-core.md`
 **Priority:** CRITICAL (always use for issue operations)
 
 **MUST USE FOR:**
@@ -120,13 +120,13 @@ This project uses specialized capabilities. Always check for existing capabiliti
 
 **Quick Start:**
 ```python
-from issue_tracker.backends.gitea import GiteaBackend
+from issue_core.backends.gitea import GiteaBackend
 backend = GiteaBackend()
 backend.connect(config)
 issues = backend.list_issues()
 ```
 
-**Full Documentation:** See `.claude/capabilities/issue-facade.md`
+**Full Documentation:** See `.claude/capabilities/issue-core.md`
 EOF
             echo "✓ Created $CONTEXT_FILE"
         else
@@ -138,7 +138,7 @@ EOF
         echo "✓ Added to Claude Code context"
         echo ""
         echo "Files created:"
-        echo "  - $PROJECT_ROOT/.claude/capabilities/issue-facade.md"
+        echo "  - $PROJECT_ROOT/.claude/capabilities/issue-core.md"
         echo "  - $CONTEXT_FILE"
         ;;
 
@@ -148,15 +148,15 @@ EOF
         mkdir -p "$PROJECT_ROOT/.claude/commands"
 
         cat > "$PROJECT_ROOT/.claude/commands/use-issues.md" << 'EOF'
-You are working with issue tracking. Use the **issue-facade capability**:
+You are working with issue tracking. Use the **issue-core capability**:
 
 ## Available API
 
 **Python (Recommended):**
 ```python
-from issue_tracker.backends.gitea import GiteaBackend
-from issue_tracker.core.models import Issue, Label, IssueState
-from issue_tracker.core.interfaces import IssueFilter
+from issue_core.backends.gitea import GiteaBackend
+from issue_core.core.models import Issue, Label, IssueState
+from issue_core.core.interfaces import IssueFilter
 
 backend = GiteaBackend()
 backend.connect(config)
@@ -193,7 +193,7 @@ issue close 42 --comment="Fixed"
 
 ## Full Documentation
 
-See `capabilities/issue-facade/AGENT_INTEGRATION.md` for:
+See `capabilities/issue-core/AGENT_INTEGRATION.md` for:
 - Complete API reference
 - Coordination patterns
 - Error handling
@@ -206,7 +206,7 @@ EOF
         echo "Usage in Claude Code:"
         echo "  /use-issues"
         echo ""
-        echo "This will inject issue-facade context into the conversation."
+        echo "This will inject issue-core context into the conversation."
         ;;
 
     5)
@@ -250,7 +250,7 @@ EOF
         mkdir -p "$PROJECT_ROOT/.claude/context"
 
         cp "$CAPABILITY_DIR/.capability/agent-context.md" \
-           "$PROJECT_ROOT/.claude/capabilities/issue-facade.md"
+           "$PROJECT_ROOT/.claude/capabilities/issue-core.md"
 
         # Create context file if not exists
         CONTEXT_FILE="$PROJECT_ROOT/.claude/context/capabilities.md"
@@ -258,21 +258,21 @@ EOF
             cat > "$CONTEXT_FILE" << 'EOF'
 # Available Capabilities
 
-## Issue Tracking: issue-facade
+## Issue Tracking: issue-core
 
 **CRITICAL:** Always use this for issue operations. Never bypass with direct API calls.
 
-**Docs:** `.claude/capabilities/issue-facade.md`
+**Docs:** `.claude/capabilities/issue-core.md`
 **Usage:** `/use-issues`
 EOF
         fi
 
         # Create slash command
         cat > "$PROJECT_ROOT/.claude/commands/use-issues.md" << 'EOF'
-Use the issue-facade capability for all issue tracking operations.
+Use the issue-core capability for all issue tracking operations.
 
-**Quick reference:** See `.claude/capabilities/issue-facade.md`
-**Examples:** See `capabilities/issue-facade/examples/agents/`
+**Quick reference:** See `.claude/capabilities/issue-core.md`
+**Examples:** See `capabilities/issue-core/examples/agents/`
 
 **DO NOT use direct API calls or platform CLIs!**
 EOF
@@ -285,7 +285,7 @@ EOF
         echo ""
         issue --version && echo "✓ CLI works" || echo "❌ CLI not working"
         issue backend list | grep -q "default" && echo "✓ Backend configured" || echo "⚠️  Backend not configured"
-        [ -f "$PROJECT_ROOT/.claude/capabilities/issue-facade.md" ] && echo "✓ Claude context exists" || echo "❌ Claude context missing"
+        [ -f "$PROJECT_ROOT/.claude/capabilities/issue-core.md" ] && echo "✓ Claude context exists" || echo "❌ Claude context missing"
         [ -f "$PROJECT_ROOT/.claude/commands/use-issues.md" ] && echo "✓ Slash command exists" || echo "❌ Slash command missing"
 
         echo ""
@@ -294,7 +294,7 @@ EOF
         echo "Next steps:"
         echo "  1. Test: issue list --limit=5"
         echo "  2. In Claude Code: /use-issues"
-        echo "  3. See examples: capabilities/issue-facade/examples/agents/"
+        echo "  3. See examples: capabilities/issue-core/examples/agents/"
         ;;
 
     0)