feat: establish read-only DocForge MCP foundation

tests/fixtures/alpha/.docforge/project.toml

@@ -0,0 +1,31 @@
+schema_version = 1
+project_id = "alpha-docs"
+title = "Alpha Documentation"
+adapter = "generic"
+
+[sources]
+content_roots = ["docs/content"]
+authority_files = ["POLICY.md"]
+
+[derived]
+cache_root = ".docforge/cache"
+index = ".docforge/cache/index.sqlite3"
+
+[graph]
+allowed_relations = ["depends_on", "proves", "supersedes", "relates_to", "returns_to"]
+
+[limits]
+max_source_bytes = 100000
+max_nodes = 100
+max_query_chars = 200
+max_results = 20
+max_traversal_depth = 4
+max_context_tokens = 2000
+
+[[profiles]]
+id = "active"
+families = ["guide", "proof"]
+statuses = ["active", "approved"]
+required_nodes = ["guide.workflow"]
+token_budget = 600
+dependency_depth = 2

tests/fixtures/alpha/POLICY.md

@@ -0,0 +1,3 @@
+# Alpha policy
+
+Canonical source wins over generated output.

tests/fixtures/alpha/docs/content/foundation.md

@@ -0,0 +1,12 @@
++++
+schema_version = 1
+id = "guide.foundation"
+title = "Documentation foundation"
+family = "guide"
+authority = "authoritative"
+status = "approved"
+tags = ["foundation", "canonical"]
+summary = "Defines which Alpha files own documentation facts."
++++
+
+Alpha stores canonical facts in its content directory. Derived indexes may be deleted and rebuilt.

tests/fixtures/alpha/docs/content/proof.toml

@@ -0,0 +1,11 @@
+[[nodes]]
+schema_version = 1
+id = "proof.validation"
+title = "Validation proof"
+family = "proof"
+authority = "derived"
+status = "approved"
+tags = ["proof", "validation"]
+summary = "Records the fixture validation result."
+content = "The fixture contains unique nodes, valid relationships, and confined source paths."
+proves = ["guide.workflow"]

tests/fixtures/alpha/docs/content/workflow.md

@@ -0,0 +1,13 @@
++++
+schema_version = 1
+id = "guide.workflow"
+title = "Editing workflow"
+family = "guide"
+authority = "approved_plan"
+status = "active"
+tags = ["workflow", "editing"]
+summary = "Requires validation before documentation changes are integrated."
+depends_on = ["guide.foundation"]
++++
+
+Editors change canonical nodes, validate relationships, inspect the diff, and rebuild derived output.