refactor: replace orchestrator/verifier chain with direct LiteLLM calls

Drop the three-layer Claude subprocess orchestration (local model →
Claude verifier → cloud escalation). Skills now call LiteLLM directly
and return plain text to Claude Code, which decides what to do with it.

- Delete executor, orchestrator, verifier, result, attempts packages
- Simplify LiteLLMExecutor: Run(Request)→Result becomes Complete(model,sys,user)→(string,int64,error)
- Replace ExecutorFn with CompleteFunc in all 6 skill configs
- Rewrite all skill handlers to call Complete and return {"text","model","duration_ms"}
- Simplify config/models: remove Verifier/LlamaSwapURL, add ModelFor
- Bump version to v0.5.0

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

internal/skills/trainer/handlers_test.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"testing"
 
-	iexec "github.com/mathiasbq/supervisor/internal/exec"
 	"github.com/mathiasbq/supervisor/internal/session"
 	"github.com/mathiasbq/supervisor/internal/skills/trainer"
 	"github.com/stretchr/testify/assert"
@@ -31,52 +30,44 @@ func TestTrainerRequiresSessionID(t *testing.T) {
 func TestTrainerCallsReaderThenWriter(t *testing.T) {
 	sessDir := t.TempDir()
 	require.NoError(t, session.Append(sessDir, "sess-1", session.Entry{
-		SessionID: "sess-1", Skill: "tdd", Phase: "red", FinalStatus: "pass",
+		SessionID: "sess-1", Skill: "tdd", Phase: "red", FinalStatus: "ok",
 		Message: "wrote failing test", FilePath: "internal/foo/foo_test.go",
 	}))
 
 	callCount := 0
 	var readerTask, writerTask string
 
-	fakeFn := func(_ context.Context, req iexec.Request) (iexec.Result, error) {
+	fakeFn := func(_ context.Context, _, sys, user string) (string, int64, error) {
 		callCount++
 		if callCount == 1 {
 			// reader call
-			readerTask = req.TaskPrompt
-			return iexec.Result{
-				Status: "pass", Phase: "trainer", Skill: "trainer",
-				RunnerOutput: `[{"type":"sft","moment":"first-pass clean TDD","score":4}]`,
-				Verified: true, ModelUsed: "self", Message: "1 sft candidate found",
-			}, nil
+			readerTask = user
+			return "1 sft candidate found: first-pass clean TDD", 60, nil
 		}
 		// writer call
-		writerTask = req.TaskPrompt
-		return iexec.Result{
-			Status: "pass", Phase: "trainer", Skill: "trainer",
-			FilePath: sessDir + "/training-data/sft/sess-1.jsonl",
-			Verified: true, ModelUsed: "self", Message: "1 sft pair written",
-		}, nil
+		writerTask = user
+		return "written 1 knowledge entry to brain/knowledge/tdd-patterns.md", 70, nil
 	}
 
 	sk := trainer.New(trainer.Config{
 		ReaderPrompt: "reader rules",
 		WriterPrompt: "writer rules",
-		ExecutorFn:   fakeFn,
+		CompleteFunc: fakeFn,
 		SessionsDir:  sessDir,
 		BrainDir:     t.TempDir(),
 	})
 	out, err := sk.Handle(context.Background(), "trainer", json.RawMessage(`{"session_id":"sess-1"}`))
 	require.NoError(t, err)
 
-	assert.Equal(t, 2, callCount, "executor must be called exactly twice: reader then writer")
+	assert.Equal(t, 2, callCount, "complete must be called exactly twice: reader then writer")
 	assert.Contains(t, readerTask, "role: reader")
 	assert.Contains(t, readerTask, "sess-1")
-	assert.Contains(t, readerTask, "wrote failing test") // session history in reader prompt
+	assert.Contains(t, readerTask, "wrote failing test")
 	assert.Contains(t, writerTask, "role: writer")
-	assert.Contains(t, writerTask, "sft candidate") // reader output passed to writer
+	assert.Contains(t, writerTask, "sft candidate")
 
-	var result iexec.Result
+	var result map[string]any
 	require.NoError(t, json.Unmarshal(out, &result))
-	assert.Equal(t, "trainer", result.Phase)
-	assert.Equal(t, "pass", result.Status)
+	assert.Contains(t, result["reader_analysis"], "sft candidate")
+	assert.Contains(t, result["writer_output"], "knowledge entry")
 }