feat(runtime): replace tokio+reqwest with asupersync async runtime

- Add HTTP adapter layer (src/http.rs) wrapping asupersync h1 client
- Migrate gitlab client, graphql, and ollama to HTTP adapter
- Swap entrypoint from #[tokio::main] to RuntimeBuilder::new().block_on()
- Rewrite signal handler for asupersync (RuntimeHandle::spawn + ctrl_c())
- Migrate rate limiter sleeps to asupersync::time::sleep(wall_now(), d)
- Add asupersync-native HTTP integration tests
- Convert timeline_seed_tests to RuntimeBuilder pattern

Phases 1-3 of asupersync migration (atomic: code won't compile without all pieces).

src/cli/commands/doctor.rs

@@ -385,25 +385,11 @@ async fn check_ollama(config: Option<&Config>) -> OllamaCheck {
     let base_url = &config.embedding.base_url;
     let model = &config.embedding.model;
 
-    let client = match reqwest::Client::builder()
-        .timeout(std::time::Duration::from_secs(2))
-        .build()
-    {
-        Ok(client) => client,
-        Err(e) => {
-            return OllamaCheck {
-                result: CheckResult {
-                    status: CheckStatus::Warning,
-                    message: Some(format!("Failed to build HTTP client: {e}")),
-                },
-                url: Some(base_url.clone()),
-                model: Some(model.clone()),
-            };
-        }
-    };
+    let client = crate::http::Client::with_timeout(std::time::Duration::from_secs(2));
+    let url = format!("{base_url}/api/tags");
 
-    match client.get(format!("{base_url}/api/tags")).send().await {
-        Ok(response) if response.status().is_success() => {
+    match client.get(&url, &[]).await {
+        Ok(response) if response.is_success() => {
             #[derive(serde::Deserialize)]
             struct TagsResponse {
                 models: Option<Vec<ModelInfo>>,
@@ -413,7 +399,7 @@ async fn check_ollama(config: Option<&Config>) -> OllamaCheck {
                 name: String,
             }
 
-            match response.json::<TagsResponse>().await {
+            match response.json::<TagsResponse>() {
                 Ok(data) => {
                     let models = data.models.unwrap_or_default();
                     let model_names: Vec<&str> = models
@@ -462,7 +448,7 @@ async fn check_ollama(config: Option<&Config>) -> OllamaCheck {
         Ok(response) => OllamaCheck {
             result: CheckResult {
                 status: CheckStatus::Warning,
-                message: Some(format!("Ollama responded with {}", response.status())),
+                message: Some(format!("Ollama responded with {}", response.status)),
             },
             url: Some(base_url.clone()),
             model: Some(model.clone()),

src/cli/commands/ingest/run.rs

@@ -271,11 +271,11 @@ async fn run_ingest_inner(
 
     let token = config.gitlab.resolve_token()?;
 
-    let client = GitLabClient::new(
+    let client = Arc::new(GitLabClient::new(
         &config.gitlab.base_url,
         &token,
         Some(config.sync.requests_per_second),
-    );
+    ));
 
     let projects = get_projects_to_sync(&conn, &config.projects, project_filter)?;
 
@@ -352,7 +352,7 @@ async fn run_ingest_inner(
 
     let project_results: Vec<Result<ProjectIngestOutcome>> = stream::iter(projects.iter())
         .map(|(local_project_id, gitlab_project_id, path)| {
-            let client = client.clone();
+            let client = Arc::clone(&client);
             let db_path = db_path.clone();
             let config = config.clone();
             let resource_type = resource_type_owned.clone();