homelab: add tf verbs + stack/git-crypt substrate

Adds the tf verb-group and the resolver substrate beneath it, continuing the
v0.1 infra-loop build.

- substrate: findInfraRoot (walk up to terragrunt.hcl + stacks/), stack→dir
  resolver, and repo/remote/git-crypt detection (preferRemote forgejo>origin,
  hasGitCryptAttr, gitCryptFlags) — the last is for `work` next.
- tf plan/validate/fmt/force-unlock/apply, resolving the stack from cwd and
  delegating to scripts/tg (which owns state decrypt/encrypt, the Vault lock,
  and the ingress auth-comment check) rather than calling terragrunt directly.
- tf apply is presence-coupled: claims stack:<name>, ALWAYS releases on exit
  (normal, error, or SIGINT/SIGTERM via sync.Once + signal handler) — fixing
  the documented ~200-claim leak — and prints an out-of-band reminder since CI
  applies canonically on push.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cli/cmd_tf.go

@@ -0,0 +1,122 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strings"
+	"sync"
+	"syscall"
+)
+
+func tfCommands() []Command {
+	return []Command{
+		{Path: []string{"tf", "plan"}, Tier: TierRead,
+			Summary: "terragrunt plan a stack (via scripts/tg)", Run: tfPassthrough("plan")},
+		{Path: []string{"tf", "validate"}, Tier: TierRead,
+			Summary: "terragrunt validate a stack", Run: tfPassthrough("validate")},
+		{Path: []string{"tf", "fmt"}, Tier: TierRead,
+			Summary: "terraform fmt a stack's files", Run: tfFmt},
+		{Path: []string{"tf", "force-unlock"}, Tier: TierWrite,
+			Summary: "release a stuck terraform state lock (needs <stack> <lock-id>)", Run: tfForceUnlock},
+		{Path: []string{"tf", "apply"}, Tier: TierWrite,
+			Summary: "terragrunt apply a stack — presence-coupled, out-of-band", Run: tfApply},
+	}
+}
+
+// firstPositional returns the first non-flag arg and the remaining args with it removed.
+func firstPositional(args []string) (string, []string) {
+	for i, a := range args {
+		if !strings.HasPrefix(a, "-") {
+			rest := append(append([]string{}, args[:i]...), args[i+1:]...)
+			return a, rest
+		}
+	}
+	return "", args
+}
+
+// resolveTfStack finds the infra root (from cwd) and the stack directory named
+// by the first positional arg, returning the remaining args.
+func resolveTfStack(args []string) (infraRoot, stackName, stackDir string, rest []string, err error) {
+	stackName, rest = firstPositional(args)
+	if stackName == "" {
+		err = fmt.Errorf("missing <stack> argument")
+		return
+	}
+	cwd, e := os.Getwd()
+	if e != nil {
+		err = e
+		return
+	}
+	infraRoot, err = findInfraRoot(cwd)
+	if err != nil {
+		return
+	}
+	stackDir, err = resolveStack(infraRoot, stackName)
+	return
+}
+
+func tgPath(infraRoot string) string { return filepath.Join(infraRoot, "scripts", "tg") }
+
+// tfPassthrough runs `scripts/tg <verb> [extra]` in the stack directory.
+func tfPassthrough(verb string) func([]string) error {
+	return func(args []string) error {
+		infraRoot, _, stackDir, rest, err := resolveTfStack(args)
+		if err != nil {
+			return err
+		}
+		return runStreamingIn(stackDir, tgPath(infraRoot), append([]string{verb}, rest...)...)
+	}
+}
+
+func tfFmt(args []string) error {
+	_, _, stackDir, _, err := resolveTfStack(args)
+	if err != nil {
+		return err
+	}
+	return runStreamingIn(stackDir, "terraform", "fmt", "-recursive", ".")
+}
+
+func tfForceUnlock(args []string) error {
+	infraRoot, _, stackDir, rest, err := resolveTfStack(args)
+	if err != nil {
+		return err
+	}
+	if len(rest) < 1 {
+		return fmt.Errorf("usage: homelab tf force-unlock <stack> <lock-id>")
+	}
+	return runStreamingIn(stackDir, tgPath(infraRoot), "force-unlock", "-force", rest[0])
+}
+
+// tfApply applies a stack out-of-band: claim the stack on the presence board,
+// ALWAYS release on exit (normal, error, or signal — fixing the claim leak),
+// and warn that CI applies canonically on push.
+func tfApply(args []string) error {
+	infraRoot, stackName, stackDir, _, err := resolveTfStack(args)
+	if err != nil {
+		return err
+	}
+	label := "stack:" + stackName
+	fmt.Fprintf(os.Stderr,
+		"homelab: out-of-band apply of %q — CI applies canonically on push to master.\n", stackName)
+
+	if err := presenceClaim(label, "homelab tf apply "+stackName); err != nil {
+		return fmt.Errorf("presence claim failed (run `vault login -method=oidc`?): %w", err)
+	}
+	// Release exactly once, whether we exit normally, on error, or on signal —
+	// sync.Once makes the defer and the signal goroutine safe to both call it.
+	var once sync.Once
+	release := func() { once.Do(func() { _ = presenceRelease(label) }) }
+	defer release()
+
+	sig := make(chan os.Signal, 1)
+	signal.Notify(sig, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		<-sig
+		release()
+		os.Exit(130)
+	}()
+
+	return runStreamingIn(stackDir, tgPath(infraRoot), "apply", "--non-interactive")
+}