Run wrapped tools directly as vintner <tool> ..., no PATH needed

`vintner cl ...`, `vintner msbuild ...`, etc. now work without adding
<dest>/bin/<arch> to PATH or relying on the same-directory symlinks
`install` sets up there. wrapper.Run gained an explicit binDir
parameter (empty string preserves the existing os.Executable()-based
self-location for the ordinary multi-call/symlink case) so
cmd/vintner's new runTool can point it at a resolved toolchain
directory instead.

Resolution order: VINTNER_BIN if set (same meaning as `env --bin` -
point it at a <dest>/bin/<arch> directory directly, for a non-default
--dest or a specific architecture), else <defaultToolchainDir>/bin/
<hostArch> - the layout a plain `vintner download && vintner install`
with no --dest override produces. A missing toolchain gets a clear
error pointing at both fixes, rather than bubbling up whatever
wineenv.Load's env.json error looks like.

Also fixed shell completion falling out of sync with the actual tool
list: the bash/zsh scripts previously hand-copied tool/flag names
(and had already gone stale once - --with-dxsdk was missing from the
download flag completions since it was added). The tool name list is
now generated from wrapper.ToolNames() instead of hand-maintained,
and both scripts now complete tool names too, so `vintner <TAB>`
suggests `cl`, `link`, `msbuild`, etc. alongside the management
subcommands.

Verified end-to-end with a minimal PATH (/usr/bin:/bin only, no
toolchain dir on it at all): `vintner cl /nologo hello.c` compiled
successfully, and `vintner msbuild -t:Rebuild ...` rebuilt the same
real KMDF driver verified earlier this session - both via the default
~/.vintner/bin/<hostArch> resolution, no VINTNER_BIN override needed.

internal/i18n/i18n.go

@@ -84,7 +84,10 @@ has many, including --with-wdk, --with-dxsdk, --list-workloads,
 Language: set VINTNER_LANG=ru (or LANG=ru_RU...) for Russian output.
 Completion: source <(vintner completion bash)  # or zsh
 
-Once installed, add <dir>/bin/<arch> to PATH and invoke the tools directly:
+Once installed, add <dir>/bin/<arch> to PATH and invoke the tools directly,
+or skip PATH and run them through vintner itself - "vintner cl ...",
+"vintner msbuild ...", etc. (set VINTNER_BIN to a <dir>/bin/<arch> if it's
+not the default ~/.vintner/bin/<host-arch>):
   cl, link, lib, ml, ml64, mc, midl, mt, rc, dumpbin, msbuild, nmake, armasm, armasm64, cmd, findstr
 `,
 		RU: `vintner — кросс-компиляция настоящим MSVC на Linux через Wine
@@ -104,9 +107,13 @@ Once installed, add <dir>/bin/<arch> to PATH and invoke the tools directly:
 
 --dest/[каталог] по умолчанию — ~/.vintner.
 Язык: установите VINTNER_LANG=en (или LANG=en_US...) для вывода на английском.
+Можно не трогать PATH: "vintner cl ...", "vintner msbuild ..." и т.д. работают
+напрямую (VINTNER_BIN — если каталог не стандартный ~/.vintner/bin/<hostarch>).
 Автодополнение: source <(vintner completion bash)  # или zsh
 
-После установки добавьте <dir>/bin/<arch> в PATH и вызывайте инструменты напрямую:
+После установки добавьте <dir>/bin/<arch> в PATH и вызывайте инструменты
+напрямую, либо не трогая PATH — «vintner cl ...», «vintner msbuild ...»
+и т.д.:
   cl, link, lib, ml, ml64, mc, midl, mt, rc, dumpbin, msbuild, nmake, armasm, armasm64, cmd, findstr
 `,
 	},
@@ -124,8 +131,8 @@ Once installed, add <dir>/bin/<arch> to PATH and invoke the tools directly:
 		RU: "Каталог не указан, используется значение по умолчанию: %s",
 	},
 	"install.done": {
-		EN: "Done. Add %s to PATH to use cl, link, lib, ...",
-		RU: "Готово. Добавьте %s в PATH, чтобы использовать cl, link, lib и т.д.",
+		EN: "Done. Add %s to PATH to use cl, link, lib, ... directly, or run them as \"vintner cl\", \"vintner link\", etc. without touching PATH.",
+		RU: "Готово. Добавьте %s в PATH, чтобы использовать cl, link, lib и т.д. напрямую, либо запускайте их как «vintner cl», «vintner link» и т.д., не трогая PATH.",
 	},
 
 	"env.usage": {

internal/wrapper/run.go

@@ -30,7 +30,15 @@ const toolRelayName = "toolrelay.exe"
 
 // Run executes the named multi-call tool with args, exactly as the original
 // bash wrappers would, and returns the process exit code.
-func Run(tool string, args []string) int {
+//
+// binDir is the <dest>/bin/<arch> directory holding env.json for this
+// invocation. Pass "" for the ordinary multi-call case (invoked as `cl`,
+// `link`, etc. via a same-directory symlink) to have it resolved from the
+// running binary's own location; a non-empty value is for `vintner <tool>
+// ...` direct dispatch (see cmd/vintner's runTool), which isn't running
+// from inside any particular <dest>/bin/<arch> and so has nothing to
+// resolve on its own.
+func Run(tool string, args []string, binDir string) int {
 	if nativeTools[tool] {
 		return runNative(tool, args)
 	}
@@ -41,19 +49,23 @@ func Run(tool string, args []string) int {
 		return 127
 	}
 
-	// os.Executable() (backed by /proc/self/exe on Linux) fully resolves
-	// symlinks, unlike os.Args[0]: not every shell passes a PATH-resolved
-	// absolute path as argv[0] (some just pass the bare command name), which
-	// would make an argv[0]-based lookup resolve against the caller's cwd
-	// instead of the actual install dir. `install` sets each arch dir up
-	// with its own local copy of the binary precisely so this resolves to
-	// <dest>/bin/<arch>, not <dest>/bin.
-	exePath, err := os.Executable()
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "vintner:", err)
-		return 1
+	scriptDir := binDir
+	if scriptDir == "" {
+		// os.Executable() (backed by /proc/self/exe on Linux) fully resolves
+		// symlinks, unlike os.Args[0]: not every shell passes a
+		// PATH-resolved absolute path as argv[0] (some just pass the bare
+		// command name), which would make an argv[0]-based lookup resolve
+		// against the caller's cwd instead of the actual install dir.
+		// `install` sets each arch dir up with its own local copy of the
+		// binary precisely so this resolves to <dest>/bin/<arch>, not
+		// <dest>/bin.
+		exePath, err := os.Executable()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "vintner:", err)
+			return 1
+		}
+		scriptDir = filepath.Dir(exePath)
 	}
-	scriptDir := filepath.Dir(exePath)
 
 	cfg, err := wineenv.Load(scriptDir)
 	if err != nil {

internal/wrapper/tools.go

@@ -4,7 +4,11 @@
 // filtering its output.
 package wrapper
 
-import "github.com/Cheviiot/vintner/internal/wineenv"
+import (
+	"sort"
+
+	"github.com/Cheviiot/vintner/internal/wineenv"
+)
 
 // dirKind selects which install directory a tool's real .exe lives in.
 type dirKind int
@@ -46,6 +50,32 @@ var Tools = map[string]spec{
 // nativeTools are handled entirely without Wine.
 var nativeTools = map[string]bool{"cmd": true, "findstr": true}
 
+// IsTool reports whether name is a recognized wrapped tool - either a
+// Wine-hosted one in Tools or a native shim in nativeTools. Shared between
+// the ordinary multi-call dispatch (invoked *as* one of these names via a
+// same-directory symlink) and `vintner <tool> ...` direct dispatch, so both
+// recognize exactly the same set of names.
+func IsTool(name string) bool {
+	_, ok := Tools[name]
+	return ok || nativeTools[name]
+}
+
+// ToolNames returns every recognized tool name, sorted - Tools and
+// nativeTools combined. Used to generate shell completion without a
+// separate hand-maintained list that could drift from the real set (as
+// happened once already with a stale --with-dxsdk completion entry).
+func ToolNames() []string {
+	names := make([]string, 0, len(Tools)+len(nativeTools))
+	for name := range Tools {
+		names = append(names, name)
+	}
+	for name := range nativeTools {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	return names
+}
+
 func (s spec) exeDir(p *wineenv.Paths) string {
 	switch s.dir {
 	case dirSDK:

internal/wrapper/tools_test.go

@@ -43,3 +43,21 @@ func TestEveryToolHasAnExeName(t *testing.T) {
 		}
 	}
 }
+
+func TestIsTool(t *testing.T) {
+	for name := range Tools {
+		if !IsTool(name) {
+			t.Errorf("IsTool(%q) = false, want true (it's in Tools)", name)
+		}
+	}
+	for name := range nativeTools {
+		if !IsTool(name) {
+			t.Errorf("IsTool(%q) = false, want true (it's in nativeTools)", name)
+		}
+	}
+	for _, name := range []string{"download", "install", "env", "version", "help", "completion", "frobnicate", ""} {
+		if IsTool(name) {
+			t.Errorf("IsTool(%q) = true, want false", name)
+		}
+	}
+}