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/config/models_test.go

@@ -11,9 +11,6 @@ import (
 )
 
 const testYAML = `
-verifier: claude-sonnet-4-6
-llama_swap_url: http://koala:8080
-
 default_chain:
   - ollama/qwen3-coder-30b-tuned
   - claude-sonnet-4-6
@@ -37,44 +34,20 @@ func writeModels(t *testing.T, content string) string {
 	return f
 }
 
-func TestModelsVerifier(t *testing.T) {
+func TestModelsModelForSkillWithEntry(t *testing.T) {
 	m, err := config.LoadModels(writeModels(t, testYAML))
 	require.NoError(t, err)
-	assert.Equal(t, "claude-sonnet-4-6", m.Verifier())
+	assert.Equal(t, "ollama/devstral-tuned", m.ModelFor("review", ""))
 }
 
-func TestModelsLlamaSwapURL(t *testing.T) {
+func TestModelsModelForDefaultFallback(t *testing.T) {
 	m, err := config.LoadModels(writeModels(t, testYAML))
 	require.NoError(t, err)
-	assert.Equal(t, "http://koala:8080", m.LlamaSwapURL())
+	assert.Equal(t, "ollama/qwen3-coder-30b-tuned", m.ModelFor("trainer", ""))
 }
 
-func TestModelsChainForSkillOverride(t *testing.T) {
+func TestModelsModelForCallerOverride(t *testing.T) {
 	m, err := config.LoadModels(writeModels(t, testYAML))
 	require.NoError(t, err)
-
-	chain := m.ChainFor("review", "")
-	require.Len(t, chain, 3)
-	assert.Equal(t, "ollama/devstral-tuned", chain[0])
-	assert.Equal(t, "ollama/gemma4", chain[1])
-	assert.Equal(t, "claude-sonnet-4-6", chain[2])
-}
-
-func TestModelsChainForDefaultFallback(t *testing.T) {
-	m, err := config.LoadModels(writeModels(t, testYAML))
-	require.NoError(t, err)
-
-	chain := m.ChainFor("trainer", "") // not in skills map
-	require.Len(t, chain, 2)
-	assert.Equal(t, "ollama/qwen3-coder-30b-tuned", chain[0])
-	assert.Equal(t, "claude-sonnet-4-6", chain[1])
-}
-
-func TestModelsChainForCallerOverride(t *testing.T) {
-	m, err := config.LoadModels(writeModels(t, testYAML))
-	require.NoError(t, err)
-
-	chain := m.ChainFor("review", "claude-opus-4-6")
-	require.Len(t, chain, 1)
-	assert.Equal(t, "claude-opus-4-6", chain[0])
+	assert.Equal(t, "claude-opus-4-6", m.ModelFor("review", "claude-opus-4-6"))
 }