feat(cli): align slash help/status/model handling

Centralize slash command parsing in the commands crate so the REPL can share help metadata and grow toward Claude Code parity without duplicating handlers. This adds shared /help and /model parsing, routes REPL dispatch through the shared parser, and upgrades /status to report model and token totals.

To satisfy the required verification gate, this also fixes existing workspace clippy and test blockers in runtime, tools, api, and compat-harness that were unrelated to the new command behavior but prevented fmt/clippy/test from passing cleanly.

Constraint: Preserve existing prompt-mode and REPL behavior while adding real slash commands

Constraint: cargo fmt, clippy, and workspace tests must pass before shipping command-surface work

Rejected: Keep command handling only in main.rs | would deepen duplication with commands crate and resume path

Confidence: high

Scope-risk: moderate

Reversibility: clean

Directive: Extend new slash commands through the shared commands crate first so REPL and resume entrypoints stay consistent

Tested: cargo fmt; cargo clippy --workspace --all-targets -- -D warnings; cargo test --workspace

Not-tested: live Anthropic network execution beyond existing mocked/integration coverage

rust/crates/compat-harness/src/lib.rs

@@ -24,9 +24,10 @@ impl UpstreamPaths {
             .as_ref()
             .canonicalize()
             .unwrap_or_else(|_| workspace_dir.as_ref().to_path_buf());
-        let repo_root = workspace_dir
+        let primary_repo_root = workspace_dir
             .parent()
             .map_or_else(|| PathBuf::from(".."), Path::to_path_buf);
+        let repo_root = resolve_upstream_repo_root(&primary_repo_root);
         Self { repo_root }
     }
 
@@ -53,6 +54,42 @@ pub struct ExtractedManifest {
     pub bootstrap: BootstrapPlan,
 }
 
+fn resolve_upstream_repo_root(primary_repo_root: &Path) -> PathBuf {
+    let candidates = upstream_repo_candidates(primary_repo_root);
+    candidates
+        .into_iter()
+        .find(|candidate| candidate.join("src/commands.ts").is_file())
+        .unwrap_or_else(|| primary_repo_root.to_path_buf())
+}
+
+fn upstream_repo_candidates(primary_repo_root: &Path) -> Vec<PathBuf> {
+    let mut candidates = vec![primary_repo_root.to_path_buf()];
+
+    if let Some(explicit) = std::env::var_os("CLAUDE_CODE_UPSTREAM") {
+        candidates.push(PathBuf::from(explicit));
+    }
+
+    for ancestor in primary_repo_root.ancestors().take(4) {
+        candidates.push(ancestor.join("claude-code"));
+        candidates.push(ancestor.join("clawd-code"));
+    }
+
+    candidates.push(
+        primary_repo_root
+            .join("reference-source")
+            .join("claude-code"),
+    );
+    candidates.push(primary_repo_root.join("vendor").join("claude-code"));
+
+    let mut deduped = Vec::new();
+    for candidate in candidates {
+        if !deduped.iter().any(|seen: &PathBuf| seen == &candidate) {
+            deduped.push(candidate);
+        }
+    }
+    deduped
+}
+
 pub fn extract_manifest(paths: &UpstreamPaths) -> std::io::Result<ExtractedManifest> {
     let commands_source = fs::read_to_string(paths.commands_path())?;
     let tools_source = fs::read_to_string(paths.tools_path())?;