feat: Add contract type templates API endpoint

Add a new API endpoint to provide contract type templates (workflow
definitions) separate from file templates. This enables the create
contract page to dynamically show available contract types.

Changes:
- Add ContractTypeTemplate struct in templates.rs with id, name,
  description, phases, default_phase, and is_builtin fields
- Add built-in contract types: 'simple' (plan/execute) and
  'specification' (research/specify/plan/execute/review)
- Add GET /api/v1/contract-types endpoint returning all contract types
- Add frontend ContractTypeTemplate interface and listContractTypes()
  API function

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

2 files changed, 33 insertions, 0 deletions

diff --git a/makima/src/server/handlers/templates.rs b/makima/src/server/handlers/templates.rs
index 868d5b4..6d95e86 100644
--- a/makima/src/server/handlers/templates.rs
+++ b/makima/src/server/handlers/templates.rs
@@ -5,6 +5,7 @@ use serde::{Deserialize, Serialize};
 use utoipa::ToSchema;
 
 use crate::llm::templates;
+use crate::llm::templates::ContractTypeTemplate;
 
 /// Query parameters for listing templates
 #[derive(Debug, Deserialize, ToSchema)]
@@ -105,3 +106,33 @@ pub async fn get_template(
             .into_response(),
     }
 }
+
+// =============================================================================
+// Contract Type Templates (Workflow Definitions)
+// =============================================================================
+
+/// Response for listing contract types
+#[derive(Debug, Serialize, ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ListContractTypesResponse {
+    pub contract_types: Vec<ContractTypeTemplate>,
+}
+
+/// List all available contract type templates
+#[utoipa::path(
+    get,
+    path = "/api/v1/contract-types",
+    responses(
+        (status = 200, description = "Contract types retrieved successfully", body = ListContractTypesResponse)
+    ),
+    tag = "templates"
+)]
+pub async fn list_contract_types() -> impl IntoResponse {
+    let contract_types = templates::all_contract_types();
+
+    (
+        StatusCode::OK,
+        Json(ListContractTypesResponse { contract_types }),
+    )
+        .into_response()
+}
diff --git a/makima/src/server/mod.rs b/makima/src/server/mod.rs
index de20569..75f64c6 100644
--- a/makima/src/server/mod.rs
+++ b/makima/src/server/mod.rs
@@ -208,6 +208,8 @@ pub fn make_router(state: SharedState) -> Router {
         // Template endpoints
         .route("/templates", get(templates::list_templates))
         .route("/templates/{id}", get(templates::get_template))
+        // Contract type templates (workflow definitions)
+        .route("/contract-types", get(templates::list_contract_types))
         // Settings endpoints
         .route(
             "/settings/repository-history",