recover: restore untracked work from recovery branch (no Gemini changes)

Recovered files with no Claude→Agent contamination:
- docs/adr/002-task-state-machine.md
- internal/api/logs.go/logs_test.go: task-level log streaming endpoint
- internal/api/validate.go/validate_test.go: POST /api/tasks/validate
- internal/api/server_test.go, storage/db_test.go: expanded test coverage
- scripts/reset-failed-tasks, reset-running-tasks
- web/app.js, index.html, style.css: frontend improvements
- web/test/: active-tasks-tab, delete-button, filter-tabs, sort-tasks tests

Manually applied from server.go diff (skipping Claude→Agent rename):
- taskLogStore field + validateCmdPath field
- DELETE /api/tasks/{id} route + handleDeleteTask
- GET /api/tasks/{id}/logs/stream route
- POST /api/tasks/{id}/resume route + handleResumeTimedOutTask
- handleCancelTask: allow cancelling PENDING/QUEUED tasks directly

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

1 files changed, 125 insertions, 0 deletions

diff --git a/internal/api/validate.go b/internal/api/validate.go
new file mode 100644
index 0000000..d8ebde9
--- /dev/null
+++ b/internal/api/validate.go
@@ -0,0 +1,125 @@
+package api
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os/exec"
+	"time"
+)
+
+const validateTimeout = 20 * time.Second
+
+const validateSystemPrompt = `You are a task instruction reviewer for Claudomator, an AI task runner that executes tasks by running Claude as a subprocess.
+
+Analyze the given task name and instructions for clarity and completeness.
+
+Output ONLY a valid JSON object (no markdown fences, no prose, no explanation):
+
+{
+  "clarity":     "clear" | "warning" | "blocking",
+  "ready":       boolean — true if task can proceed without clarification,
+  "summary":     string — 1-2 sentence assessment,
+  "questions":   [{"text": string, "severity": "blocking" | "minor"}],
+  "suggestions": [string]
+}
+
+clarity definitions:
+- "clear": instructions are specific, actionable, and complete
+- "warning": minor ambiguities exist but task can reasonably proceed
+- "blocking": critical information is missing; task cannot succeed without clarification`
+
+type validateResult struct {
+	Clarity     string            `json:"clarity"`
+	Ready       bool              `json:"ready"`
+	Questions   []validateQuestion `json:"questions"`
+	Suggestions []string          `json:"suggestions"`
+	Summary     string            `json:"summary"`
+}
+
+type validateQuestion struct {
+	Severity string `json:"severity"`
+	Text     string `json:"text"`
+}
+
+func (s *Server) validateBinaryPath() string {
+	if s.validateCmdPath != "" {
+		return s.validateCmdPath
+	}
+	return s.claudeBinaryPath()
+}
+
+func (s *Server) handleValidateTask(w http.ResponseWriter, r *http.Request) {
+	var input struct {
+		Name  string `json:"name"`
+		Claude struct {
+			Instructions string   `json:"instructions"`
+			WorkingDir   string   `json:"working_dir"`
+			AllowedTools []string `json:"allowed_tools"`
+		} `json:"claude"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
+		return
+	}
+	if input.Name == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "name is required"})
+		return
+	}
+	if input.Claude.Instructions == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "instructions are required"})
+		return
+	}
+
+	userMsg := fmt.Sprintf("Task name: %s\n\nInstructions:\n%s", input.Name, input.Claude.Instructions)
+	if input.Claude.WorkingDir != "" {
+		userMsg += fmt.Sprintf("\n\nWorking directory: %s", input.Claude.WorkingDir)
+	}
+	if len(input.Claude.AllowedTools) > 0 {
+		userMsg += fmt.Sprintf("\n\nAllowed tools: %v", input.Claude.AllowedTools)
+	}
+
+	ctx, cancel := context.WithTimeout(r.Context(), validateTimeout)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, s.validateBinaryPath(),
+		"-p", userMsg,
+		"--system-prompt", validateSystemPrompt,
+		"--output-format", "json",
+		"--model", "haiku",
+	)
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		s.logger.Error("validate: claude subprocess failed", "error", err, "stderr", stderr.String())
+		writeJSON(w, http.StatusBadGateway, map[string]string{
+			"error": fmt.Sprintf("validation failed: %v", err),
+		})
+		return
+	}
+
+	var wrapper claudeJSONResult
+	if err := json.Unmarshal(stdout.Bytes(), &wrapper); err != nil {
+		s.logger.Error("validate: failed to parse claude JSON wrapper", "error", err, "stdout", stdout.String())
+		writeJSON(w, http.StatusBadGateway, map[string]string{
+			"error": "validation failed: invalid JSON from claude",
+		})
+		return
+	}
+
+	var result validateResult
+	if err := json.Unmarshal([]byte(extractJSON(wrapper.Result)), &result); err != nil {
+		s.logger.Error("validate: failed to parse validation result", "error", err, "result", wrapper.Result)
+		writeJSON(w, http.StatusBadGateway, map[string]string{
+			"error": "validation failed: claude returned invalid result JSON",
+		})
+		return
+	}
+
+	writeJSON(w, http.StatusOK, result)
+}