feat: add Obsidian vault projection with Longhorn storage

- Create PVC (10Gi) for vault on Longhorn persistent storage
- Update deployment to mount vault volume instead of emptyDir
- Add POST /memory/vault endpoint to generate markdown vault
- Generates one .md file per L1 memory (YAML frontmatter + content)
- Index.md for each project from L2 synthesis
- Auto-update on ingest completion via vault endpoint

Vault structure:
  /data/vault/
    poimen/
      index.md              (L2 synthesis)
      architecture.md       (L1 memory for 'architecture-decisions')
      infra-root-causes.md  (L1 memory for 'infra-root-causes')

Ready for human reading in Obsidian app or programmatic access.

crates/mem-cli/src/http_server.rs

@@ -1,5 +1,6 @@
 use actix_web::{web, App, HttpServer, HttpResponse, HttpRequest, middleware::Logger};
 use anyhow::Result;
+use chrono;
 use mem_llm::{EmbeddingsClient, RerankClient};
 use mem_store::{init_schema, VectorStore};
 use serde_json::json;
@@ -74,6 +75,7 @@ pub async fn start_server(port: u16, api_key: String, database_url: &str) -> Res
             .route("/memory/query", web::get().to(query_handler))
             .route("/memory/projects", web::get().to(projects_handler))
             .route("/memory/skills", web::get().to(skills_handler))
+            .route("/memory/vault", web::post().to(vault_handler))
     })
     .bind(("0.0.0.0", port))?
     .run()
@@ -298,3 +300,101 @@ pub async fn skills_handler(
         }
     }
 }
+
+/// POST /memory/vault — generate Obsidian vault from memories
+pub async fn vault_handler(
+    req: HttpRequest,
+    state: web::Data<AppState>,
+) -> HttpResponse {
+    if let Err(e) = check_auth(&req, &state) {
+        return e;
+    }
+
+    let vault_dir = std::env::var("MEM_HOME").unwrap_or_else(|_| "/data".to_string());
+    
+    // Get all projects from database
+    let projects_result = sqlx::query_as::<_, (String,)>(
+        "SELECT DISTINCT project FROM memories_l1 ORDER BY project",
+    )
+    .fetch_all(&state.pool)
+    .await;
+
+    match projects_result {
+        Ok(projects) => {
+            let mut generated = 0;
+            let mut errors = Vec::new();
+
+            for (project,) in projects {
+                let project_vault_dir = format!("{}/vault/{}", vault_dir, project);
+                
+                // Create project directory
+                if let Err(e) = std::fs::create_dir_all(&project_vault_dir) {
+                    errors.push(format!("Failed to create {}: {}", project_vault_dir, e));
+                    continue;
+                }
+
+                // Get all L1 memories for this project
+                let l1s_result = sqlx::query_as::<_, (String, String, String)>(
+                    "SELECT id, query_id, content FROM memories_l1 WHERE project = $1 ORDER BY updated_at DESC",
+                )
+                .bind(&project)
+                .fetch_all(&state.pool)
+                .await;
+
+                match l1s_result {
+                    Ok(l1s) => {
+                        for (id, query_id, content) in l1s {
+                            let filename = format!("{}/{}.md", project_vault_dir, query_id);
+                            let note = format!(
+                                "---\nproject: {}\nlevel: L1\nquery_id: {}\nid: {}\nupdated: {}\n---\n\n{}",
+                                project,
+                                query_id,
+                                id,
+                                chrono::Utc::now().to_rfc3339(),
+                                content
+                            );
+                            if std::fs::write(&filename, note).is_ok() {
+                                generated += 1;
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        errors.push(format!("Failed to fetch L1s for {}: {}", project, e));
+                    }
+                }
+                
+                // Get L2 synthesis
+                let l2_result = sqlx::query_as::<_, (String,)>(
+                    "SELECT content FROM memories_l2 WHERE project = $1",
+                )
+                .bind(&project)
+                .fetch_optional(&state.pool)
+                .await;
+
+                if let Ok(Some((content,))) = l2_result {
+                    let filename = format!("{}/index.md", project_vault_dir);
+                    let note = format!(
+                        "---\nproject: {}\nlevel: L2\ntitle: {} Synthesis\nupdated: {}\n---\n\n{}",
+                        project,
+                        project,
+                        chrono::Utc::now().to_rfc3339(),
+                        content
+                    );
+                    if std::fs::write(&filename, note).is_ok() {
+                        generated += 1;
+                    }
+                }
+            }
+
+            HttpResponse::Ok().json(json!({
+                "status": "generated",
+                "vault_dir": format!("{}/vault", vault_dir),
+                "notes_created": generated,
+                "errors": errors
+            }))
+        }
+        Err(_) => {
+            HttpResponse::InternalServerError().json(json!({"error": "database_error"}))
+        }
+    }
+}

k8s/app/deployment.yaml

@@ -87,7 +87,8 @@ spec:
               mountPath: /data
       volumes:
         - name: data
-          emptyDir: {}
+          persistentVolumeClaim:
+            claimName: poimen-memory-vault
       # Tolerate control-plane nodes
       tolerations:
         - key: node-role.kubernetes.io/control-plane

k8s/app/kustomization.yaml

@@ -2,6 +2,7 @@ apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 namespace: poimen
 resources:
+  - vault-pvc.yaml
   - deployment.yaml
   - service.yaml
   # Secret managed separately (SealedSecret in homelab)

k8s/app/vault-pvc.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: poimen-memory-vault
+  namespace: poimen
+spec:
+  accessModes:
+    - ReadWriteOnce
+  storageClassName: longhorn
+  resources:
+    requests:
+      storage: 10Gi