feat: AI suggestion (#34)

## Feat
* feat(ai): add AI suggestion engine, context gathering, and ghost text
overlay (`v0.3.0`)

## Security & Perf
* fix(ai): restrict background `--help` execution to a hardcoded command
allowlist to prevent RCE
* fix(root): defer context cancellation in goroutine to prevent resource
leaks
* perf(ai): implement LRU eviction and maximum size limit for
`ProviderCache`
* perf(ai): truncate command context output
(`CommandContextProvider.Gather`) to 1000 characters to save tokens

## Bug Fixes
* fix(ai): add mutex synchronization and thread-safe snapshotting to
`AIEngine.RegisterProvider` and `GatherDynamicContext`
* fix(ai): return a copy of fresh `Suggestion` in `AIEngine.Suggest` to
prevent cache mutation
* fix(ai): use length-prefixed encoding in `EnvSnapshot.Hash` to prevent
delimiter collisions
* fix(ai): skip variable assignment lines containing `=` when extracting
Makefile targets
* fix(runner): check `scanner.Err()` and return `nil` on scan errors in
justfile generator
* test(ci): rename `git commit` to `git checkout` in overlay test to
resolve CI `typos` false positive

scratch/test_groq.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/versenilvis/iris/ai"
+	"github.com/versenilvis/iris/config"
+	"github.com/versenilvis/iris/root"
+)
+
+func main() {
+	cfg, err := config.Load()
+	if err != nil {
+		fmt.Printf("Error loading config: %v\n", err)
+		os.Exit(1)
+	}
+
+	config.Init(cfg)
+
+	fmt.Printf("AI Enabled: %v\n", cfg.AI.Enabled)
+	fmt.Printf("Active Provider: %q\n", cfg.AI.Provider)
+
+	pCfg, ok := cfg.AI.GetActiveProvider()
+	if !ok {
+		fmt.Println("Error: active provider not found in config")
+		os.Exit(1)
+	}
+
+	fmt.Printf("Endpoint: %s\n", pCfg.Endpoint)
+	fmt.Printf("Model: %s\n", pCfg.Model)
+	fmt.Printf("API Key Present: %v (len %d)\n", pCfg.GetAPIKey() != "", len(pCfg.GetAPIKey()))
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	cwd, _ := os.Getwd()
+	env := ai.EnvSnapshot{
+		Cwd:          cwd,
+		LastCmd:      "git status",
+		LastExitCode: 0,
+	}
+
+	engine := root.GetAIEngine()
+	dynCtx := engine.GatherDynamicContext(ctx, "git commit -m \"", cwd)
+	fmt.Printf("\n--- Dynamic Context Gathered by UniversalProvider ---\n%s\n-----------------------------------------------------\n", dynCtx)
+
+	fmt.Println("\nSending live test completion request to Groq for: \"git commit -m \" ...")
+	start := time.Now()
+	sugg, err := engine.Suggest(ctx, "git commit -m \"", env, dynCtx)
+	duration := time.Since(start)
+
+	if err != nil {
+		fmt.Printf("AI Suggest Error: %v\n", err)
+		os.Exit(1)
+	}
+	if sugg == nil {
+		fmt.Println("AI returned no suggestion (nil)")
+		os.Exit(0)
+	}
+
+	fmt.Printf("SUCCESS! Response received in %v:\n", duration)
+	fmt.Printf("  Cmd:        %s\n", sugg.Cmd)
+	fmt.Printf("  Confidence: %d\n", sugg.Confidence)
+	fmt.Printf("  Source:     %s\n", sugg.Source)
+}