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>

pyproject.toml

@@ -3,8 +3,8 @@ requires = ["setuptools>=45", "wheel", "setuptools-scm[toml]>=6.2"]
 build-backend = "setuptools.build_meta"
 
 [project]
-name = "universal-issue-tracker"
-description = "Backend-agnostic issue tracking system with plugin architecture"
+name = "issue-core"
+description = "Authoritative task lifecycle manager for the Coulomb org — backend-agnostic with plugin architecture"
 readme = "README.md"
 requires-python = ">=3.8"
 license = {text = "MIT"}
@@ -45,6 +45,9 @@ dev = [
     "flake8>=4.0",
     "mypy>=0.900",
     "pre-commit>=2.0",
+    "httpx>=0.27",
+    "fastapi>=0.110,<1.0",
+    "pydantic>=2.0,<3.0",
 ]
 docs = [
     "sphinx>=4.0",
@@ -60,25 +63,30 @@ github = [
 jira = [
     "jira>=3.0",
 ]
+api = [
+    "fastapi>=0.110,<1.0",
+    "uvicorn[standard]>=0.27,<1.0",
+    "pydantic>=2.0,<3.0",
+]
 
 [project.urls]
-Homepage = "https://github.com/markitect/universal-issue-tracker"
-Documentation = "https://universal-issue-tracker.readthedocs.io/"
-Repository = "https://github.com/markitect/universal-issue-tracker.git"
-"Bug Tracker" = "https://github.com/markitect/universal-issue-tracker/issues"
+Homepage = "https://github.com/coulomb/issue-core"
+Documentation = "https://issue-core.readthedocs.io/"
+Repository = "https://github.com/coulomb/issue-core.git"
+"Bug Tracker" = "https://github.com/coulomb/issue-core/issues"
 
 [project.scripts]
-issue = "issue_tracker.cli.main:main"
-issue-tracker = "issue_tracker.cli.main:main"
+issue = "issue_core.cli.main:main"
+issue-core = "issue_core.cli.main:main"
 
-[tool.setuptools]
-packages = ["issue_tracker"]
+[tool.setuptools.packages.find]
+include = ["issue_core*"]
 
 [tool.setuptools.dynamic]
-version = {attr = "issue_tracker.__version__"}
+version = {attr = "issue_core.__version__"}
 
 [tool.setuptools.package-data]
-issue_tracker = ["backends/local/schema.sql"]
+issue_core = ["backends/local/schema.sql"]
 
 [tool.black]
 line-length = 100
@@ -101,7 +109,7 @@ extend-exclude = '''
 [tool.isort]
 profile = "black"
 line_length = 100
-known_first_party = ["issue_tracker"]
+known_first_party = ["issue_core"]
 
 [tool.mypy]
 python_version = "3.8"
@@ -142,7 +150,7 @@ markers = [
 ]
 
 [tool.coverage.run]
-source = ["issue_tracker"]
+source = ["issue_core"]
 omit = [
     "*/tests/*",
     "*/test_*",