feat: Launch workflow boton via agent_runner_api (issue 0116)

- Anade boton 'Launch workflow' (TI_ROCKET) que hace POST async a
  http://localhost:8486/api/runs con {issue_id, mode:'fix-issue'}.
- HTTP async via std::thread + fn_http::request (de http_request_cpp_core)
  con timeout 3s. NO bloquea el frame.
- Feature flag 'legacy_claude_fix' (default OFF) controla la visibilidad
  del boton 'Claude fix' legacy (terminal externa + claude --dangerously-
  skip-permissions). Flag leido al arrancar desde dev/feature_flags.json.
- Toast 3s con run_id devuelto por el API (o error si :8486 down /
  transport fail / HTTP non-2xx). Render thread-safe con mutex.
- CMakeLists.txt linkea cpp/functions/core/http_request.cpp.
- app.md: version 0.1.0 -> 0.2.0, uses_functions anade http_request_cpp_core,
  capability growth log con entrada v0.2.0.

CMakeLists.txt

@@ -2,6 +2,7 @@ add_imgui_app(skill_tree
     main.cpp
     ${CMAKE_SOURCE_DIR}/functions/core/parse_md_frontmatter.cpp
     ${CMAKE_SOURCE_DIR}/functions/core/compute_ring_layout.cpp
+    ${CMAKE_SOURCE_DIR}/functions/core/http_request.cpp
 )
 target_include_directories(skill_tree PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 

app.md

@@ -2,6 +2,7 @@
 name: skill_tree
 lang: cpp
 domain: tools
+version: 0.2.0
 description: "Mapa interactivo de issues+flows en anillos concentricos por estado, click para spawn agentes"
 tags: [dashboard, meta, imgui]
 icon:
@@ -10,6 +11,7 @@ icon:
 uses_functions:
   - parse_md_frontmatter_cpp_core
   - compute_ring_layout_cpp_core
+  - http_request_cpp_core
 uses_types: []
 framework: "imgui"
 entry_point: "main.cpp"
@@ -51,3 +53,14 @@ cd cpp && cmake --build build --target skill_tree -j
 ## Estado
 
 MVP fase A — sub-issue 0109a: shell + parsers issues/flows. Sin render de grafo todavia.
+
+
+## Capability growth log
+
+Una linea por bump SemVer. Bump-type segun `.claude/commands/version.md`:
+- `major`: breaking observable (CLI args, schema BBDD propia, formato wire).
+- `minor`: feature aditiva (nuevo panel, endpoint, opcion).
+- `patch`: bugfix sin cambio observable.
+
+- v0.1.0 (2026-05-18) — baseline.
+- v0.2.0 (2026-05-18) — boton `Launch workflow` (async POST :8486/api/runs via fn_http::request) + feature flag `legacy_claude_fix` que oculta el boton `Claude fix` (terminal externa). Toast con run_id 3s. Issue 0116.

main.cpp

@@ -9,8 +9,10 @@
 #include "core/logger.h"
 #include "core/parse_md_frontmatter.h"
 #include "core/compute_ring_layout.h"
+#include "core/http_request.h"
 
 #include <algorithm>
+#include <atomic>
 #include <chrono>
 #include <cmath>
 #include <cstdlib>
@@ -18,8 +20,10 @@
 #include <filesystem>
 #include <fstream>
 #include <map>
+#include <mutex>
 #include <sstream>
 #include <string>
+#include <thread>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>
@@ -241,6 +245,107 @@ static bool spawn_claude_terminal(const fs::path& registry_root) {
 #endif
 }
 
+// ---- Feature flag (legacy_claude_fix) -----------------------------------
+//
+// Reads dev/feature_flags.json once at startup, caches the boolean. Minimal
+// substring parser (no JSON library dependency at this scope — keeps the
+// boot path tiny). Looks for "legacy_claude_fix" followed by "enabled":true
+// inside the same object block. Defaults to false on any parse hiccup.
+
+static bool g_legacy_claude_fix_flag = false;
+
+static void load_feature_flags(const fs::path& registry_root) {
+    fs::path p = registry_root / "dev" / "feature_flags.json";
+    std::ifstream f(p);
+    if (!f.is_open()) {
+        g_legacy_claude_fix_flag = false;
+        return;
+    }
+    std::stringstream ss; ss << f.rdbuf();
+    std::string s = ss.str();
+    auto k = s.find("\"legacy_claude_fix\"");
+    if (k == std::string::npos) { g_legacy_claude_fix_flag = false; return; }
+    // Scan forward until the next closing brace; look for "enabled": true.
+    auto end = s.find('}', k);
+    if (end == std::string::npos) end = s.size();
+    auto en = s.find("\"enabled\"", k);
+    if (en == std::string::npos || en > end) { g_legacy_claude_fix_flag = false; return; }
+    auto colon = s.find(':', en);
+    if (colon == std::string::npos) { g_legacy_claude_fix_flag = false; return; }
+    // Skip whitespace and check for "true".
+    size_t i = colon + 1;
+    while (i < s.size() && (s[i] == ' ' || s[i] == '\t' || s[i] == '\n' || s[i] == '\r')) ++i;
+    g_legacy_claude_fix_flag = (i + 4 <= s.size() && s.compare(i, 4, "true") == 0);
+}
+
+// ---- Launch workflow (agent_runner_api POST) ----------------------------
+//
+// Async HTTP POST to http://localhost:8486/api/runs with
+// { "issue_id": "<id>", "mode": "fix-issue" }. Toast carries the resulting
+// run_id (or error) for 3 seconds. Uses fn_http::request on a detached
+// std::thread so the ImGui frame is never blocked.
+
+struct LaunchToast {
+    std::mutex   mu;
+    std::string  text;     // human-readable message
+    bool         ok = true;
+    double       expires_at = -1.0; // seconds since steady_clock epoch
+};
+
+static LaunchToast g_launch_toast;
+
+static void show_launch_toast(const std::string& msg, bool ok, double ttl_s = 3.0) {
+    std::lock_guard<std::mutex> lk(g_launch_toast.mu);
+    g_launch_toast.text       = msg;
+    g_launch_toast.ok         = ok;
+    g_launch_toast.expires_at = now_seconds() + ttl_s;
+}
+
+static std::string extract_json_string_field(const std::string& body, const std::string& key) {
+    std::string needle = "\"" + key + "\"";
+    auto k = body.find(needle);
+    if (k == std::string::npos) return {};
+    auto colon = body.find(':', k);
+    if (colon == std::string::npos) return {};
+    auto q1 = body.find('"', colon + 1);
+    if (q1 == std::string::npos) return {};
+    auto q2 = body.find('"', q1 + 1);
+    if (q2 == std::string::npos) return {};
+    return body.substr(q1 + 1, q2 - q1 - 1);
+}
+
+static void launch_workflow_async(const std::string& issue_id) {
+    show_launch_toast(std::string(TI_LOADER " launching workflow for ") + issue_id + "...", true, 30.0);
+    std::thread([issue_id]() {
+        fn_http::Request req;
+        req.method  = "POST";
+        req.url     = "http://localhost:8486/api/runs";
+        req.headers.push_back({"Content-Type", "application/json"});
+        // Minimal hand-rolled JSON — both fields are simple ASCII slugs.
+        req.body    = "{\"issue_id\":\"" + issue_id + "\",\"mode\":\"fix-issue\"}";
+        req.timeout_ms = 3000;
+        fn_http::Response resp = fn_http::request(req);
+        if (resp.status == 0) {
+            show_launch_toast(std::string("agent_runner_api unreachable: ") + resp.error, false);
+            fn_log::log_warn("skill_tree: launch_workflow %s -> transport error: %s",
+                             issue_id.c_str(), resp.error.c_str());
+            return;
+        }
+        if (resp.status >= 200 && resp.status < 300) {
+            std::string run_id = extract_json_string_field(resp.body, "run_id");
+            if (run_id.empty()) run_id = extract_json_string_field(resp.body, "id");
+            std::string msg = "run_id=" + (run_id.empty() ? std::string("(unknown)") : run_id);
+            show_launch_toast(msg, true);
+            fn_log::log_info("skill_tree: launch_workflow %s -> %s", issue_id.c_str(), msg.c_str());
+        } else {
+            char buf[128]; std::snprintf(buf, sizeof(buf), "HTTP %d", resp.status);
+            show_launch_toast(std::string(buf) + ": " + resp.body.substr(0, 80), false);
+            fn_log::log_warn("skill_tree: launch_workflow %s -> %s body=%s",
+                             issue_id.c_str(), buf, resp.body.c_str());
+        }
+    }).detach();
+}
+
 // ---- Scanner ------------------------------------------------------------
 
 static void scan_dir(const fs::path& dir, NodeKind kind, ScanResult& out) {
@@ -1123,7 +1228,12 @@ static void draw_inspector() {
 
     ImGui::Separator();
 
-    // === Claude fix: lanza terminal externa con claude ===
+    // === Launch workflow / Claude fix ===
+    //
+    // Default path: POST to http://localhost:8486/api/runs and let the
+    // agent_runner_api spawn the worker headless. Legacy path (terminal
+    // external + interactive claude CLI) sits behind feature flag
+    // `legacy_claude_fix` in dev/feature_flags.json. Default OFF (issue 0116).
     static double s_last_launch_t = -1e9;
     static bool   s_last_launch_ok = true;
     static std::string s_last_launch_id;
@@ -1131,6 +1241,20 @@ static void draw_inspector() {
     const Bucket b = status_bucket(n.status_eff);
     const bool   fixable = (b != Bucket::Done);
     if (fixable) {
+        // Launch workflow (always available): async POST to agent_runner_api.
+        ImGui::PushStyleColor(ImGuiCol_Button,        IM_COL32( 16, 185, 129, 220));
+        ImGui::PushStyleColor(ImGuiCol_ButtonHovered, IM_COL32( 52, 211, 153, 250));
+        ImGui::PushStyleColor(ImGuiCol_ButtonActive,  IM_COL32(  6, 148, 110, 255));
+        if (ImGui::Button(TI_ROCKET " Launch workflow")) {
+            launch_workflow_async(n.id);
+            fn_log::log_info("skill_tree: launch_workflow requested for %s", n.id.c_str());
+        }
+        ImGui::PopStyleColor(3);
+        ImGui::SameLine();
+        ImGui::TextDisabled("POST :8486/api/runs (fix-issue) — agent corre headless");
+
+        // Legacy Claude fix: only rendered when feature flag is ON.
+        if (g_legacy_claude_fix_flag) {
             ImGui::PushStyleColor(ImGuiCol_Button,        IM_COL32(168,  85, 247, 200));
             ImGui::PushStyleColor(ImGuiCol_ButtonHovered, IM_COL32(192, 132, 252, 240));
             ImGui::PushStyleColor(ImGuiCol_ButtonActive,  IM_COL32(147,  51, 234, 255));
@@ -1143,11 +1267,29 @@ static void draw_inspector() {
             }
             ImGui::PopStyleColor(3);
             ImGui::SameLine();
-        ImGui::TextDisabled("abre terminal externa con `claude --dangerously-skip-permissions` en fn_registry");
+            ImGui::TextDisabled("legacy: abre terminal externa con `claude --dangerously-skip-permissions`");
+        }
     } else {
         ImGui::TextDisabled("Issue done — no fix necesario.");
     }
-    if (s_last_launch_id == n.id && (now_seconds() - s_last_launch_t) < 5.0) {
+
+    // Toast del Launch workflow (run_id / error). Thread-safe lectura.
+    {
+        std::lock_guard<std::mutex> lk(g_launch_toast.mu);
+        if (!g_launch_toast.text.empty() && now_seconds() < g_launch_toast.expires_at) {
+            if (g_launch_toast.ok) {
+                ImGui::TextColored(ImVec4(0.4f, 0.95f, 0.5f, 1.0f),
+                                   TI_CHECK " %s", g_launch_toast.text.c_str());
+            } else {
+                ImGui::TextColored(ImVec4(1.0f, 0.5f, 0.5f, 1.0f),
+                                   TI_ALERT_TRIANGLE " %s", g_launch_toast.text.c_str());
+            }
+        }
+    }
+
+    // Toast legacy Claude fix.
+    if (g_legacy_claude_fix_flag &&
+        s_last_launch_id == n.id && (now_seconds() - s_last_launch_t) < 5.0) {
         if (s_last_launch_ok) {
             ImGui::TextColored(ImVec4(0.4f, 0.95f, 0.5f, 1.0f),
                                TI_CHECK " terminal lanzada (revisa Windows Terminal / WSL)");
@@ -1385,6 +1527,9 @@ static void render() {
         g_root = discover_registry_root();
         fn_log::log_info("skill_tree: discover_registry_root -> '%s'",
                          g_root.empty() ? "(empty)" : g_root.string().c_str());
+        load_feature_flags(g_root);
+        fn_log::log_info("skill_tree: legacy_claude_fix flag = %s",
+                         g_legacy_claude_fix_flag ? "ON" : "OFF");
         reload_scan();
     }
     if (g_show_tree)      draw_tree();