Add subagent demo and complete tool display name coverage

- Add demo/03-subagent.dot, renumber demos 04-08
- Add shell and spawn_agent to tool display name matcher
- Add list_dir, web_search, web_fetch, use_skill display args

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/arc-workflows/src/cli/progress.rs

@@ -101,12 +101,17 @@ fn tool_display_name(tool_name: &str, arguments: &serde_json::Value) -> String {
     let path_arg = || arg("path").or_else(|| arg("file_path")).map(|p| truncate(&shorten_path(p), 60));
 
     let detail = match tool_name {
-        "bash" | "execute_command" => arg("command").map(|c| truncate(c, 60)),
+        "bash" | "shell" | "execute_command" => arg("command").map(|c| truncate(c, 60)),
         "glob" => arg("pattern").map(String::from),
         "grep" | "ripgrep" => arg("pattern").map(|p| truncate(p, 40)),
         "read_file" | "read" => path_arg(),
         "write_file" | "write" | "create_file" => path_arg(),
         "edit_file" | "edit" => path_arg(),
+        "list_dir" => path_arg(),
+        "web_search" => arg("query").map(|q| truncate(q, 60)),
+        "web_fetch" => arg("url").map(|u| truncate(u, 60)),
+        "spawn_agent" => arg("task").map(|t| truncate(t, 60)),
+        "use_skill" => arg("skill_name").map(String::from),
         _ => None,
     };
 

demo/03-subagent.dot

@@ -0,0 +1,11 @@
+digraph SubAgent {
+    graph [goal="Research and summarize using a sub-agent"]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    research [label="Research", prompt="You have a sub-agent available via the spawn_agent tool. Spawn a sub-agent to list the files in the current directory and read the first 10 lines of any README or CLAUDE.md. Then, using the sub-agent's findings, write a 2-sentence summary of the project."]
+
+    start -> research -> exit
+}

demo/04-pipeline.dot

@@ -0,0 +1,13 @@
+digraph Pipeline {
+    graph [goal="Analyze the current directory and suggest improvements"]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    scan    [label="Scan Files", shape=parallelogram, script="find . -maxdepth 2 -type f | head -30"]
+    analyze [label="Analyze", prompt="Review the file listing from the previous step. Identify what kind of project this is and summarize its structure in 3-4 bullet points.", codergen_mode="one_shot", reasoning_effort="low"]
+    suggest [label="Suggest", prompt="Based on the analysis, suggest 3 concrete improvements to the project structure. Be specific and actionable.", codergen_mode="one_shot", reasoning_effort="low"]
+
+    start -> scan -> analyze -> suggest -> exit
+}

demo/05-branch-loop.dot

@@ -0,0 +1,16 @@
+digraph BranchLoop {
+    graph [goal="Create a Python script that passes its test suite"]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    plan      [label="Plan", prompt="Plan a small Python script (fizzbuzz.py) and a test file (test_fizzbuzz.py) using pytest. Describe what you will create.", codergen_mode="one_shot", reasoning_effort="low"]
+    implement [label="Implement", prompt="Create fizzbuzz.py and test_fizzbuzz.py as planned. Write the files to disk."]
+    validate  [label="Validate", shape=parallelogram, script="python -m pytest test_fizzbuzz.py -v 2>&1 || true"]
+    gate      [shape=diamond, label="Tests passing?"]
+
+    start -> plan -> implement -> validate -> gate
+    gate -> exit      [label="Pass", condition="outcome=success"]
+    gate -> implement [label="Fix"]
+}

demo/06-parallel.dot

@@ -0,0 +1,25 @@
+digraph Parallel {
+    graph [goal="Perform a multi-perspective code review"]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    fork [label="Fork Analysis", shape=component, join_policy="wait_all", error_policy="continue"]
+
+    security    [label="Security Audit", prompt="Examine the codebase for security concerns: hardcoded secrets, injection risks, unsafe dependencies. List findings as bullet points.", codergen_mode="one_shot", reasoning_effort="low"]
+    architecture [label="Architecture Review", prompt="Assess the codebase architecture: separation of concerns, dependency structure, modularity. List findings as bullet points.", codergen_mode="one_shot", reasoning_effort="low"]
+    quality     [label="Code Quality", prompt="Check code quality: naming conventions, dead code, test coverage gaps, error handling. List findings as bullet points.", codergen_mode="one_shot", reasoning_effort="low"]
+
+    merge  [label="Merge Findings", shape=tripleoctagon]
+    report [label="Final Report", prompt="Synthesize the security, architecture, and code quality findings into a prioritized summary report with top 5 action items.", codergen_mode="one_shot"]
+
+    start -> fork
+    fork -> security
+    fork -> architecture
+    fork -> quality
+    security -> merge
+    architecture -> merge
+    quality -> merge
+    merge -> report -> exit
+}

demo/07-human-gate.dot

@@ -0,0 +1,18 @@
+digraph HumanGate {
+    graph [goal="Propose and implement a README improvement"]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    draft   [label="Draft Proposal", prompt="Read the README.md (or note its absence). Propose a specific improvement: either create one or enhance the existing one. Describe your proposed changes clearly but do NOT make any changes yet.", codergen_mode="one_shot"]
+    approve [label="Approve Changes?", shape=hexagon]
+    apply   [label="Apply Changes", prompt="Apply the proposed README changes that were approved."]
+    skip    [label="Skip", prompt="Acknowledged. No changes made.", codergen_mode="one_shot", reasoning_effort="low"]
+
+    start -> draft -> approve
+    approve -> apply [label="[A] Approve"]
+    approve -> skip  [label="[S] Skip"]
+    apply -> exit
+    skip -> exit
+}

demo/08-multi-model.dot

@@ -0,0 +1,21 @@
+digraph MultiModel {
+    graph [
+        goal="Build and review a utility function using multiple models",
+        model_stylesheet="
+            * { llm_model: claude-haiku-4-5; llm_provider: anthropic; reasoning_effort: low; }
+            .coding { llm_model: claude-sonnet-4-5; llm_provider: anthropic; reasoning_effort: high; }
+            #review { llm_model: claude-sonnet-4-5; llm_provider: anthropic; reasoning_effort: high; }
+        "
+    ]
+    rankdir=LR
+
+    start [shape=Mdiamond, label="Start"]
+    exit  [shape=Msquare, label="Exit"]
+
+    spec     [label="Write Spec", prompt="Write a brief spec for a TypeScript string utility module with 3 functions: slugify, truncate, and capitalize. Output the spec only.", codergen_mode="one_shot"]
+    implement [label="Implement", prompt="Implement the TypeScript string utility module from the spec. Write it to string-utils.ts.", class="coding"]
+    test     [label="Write Tests", prompt="Write tests for the string utility module using Bun's test runner. Write to string-utils.test.ts.", class="coding"]
+    review   [label="Code Review", prompt="Review the implementation and tests. Check for edge cases, type safety, and correctness. Provide a brief verdict.", codergen_mode="one_shot"]
+
+    start -> spec -> implement -> test -> review -> exit
+}