prompt: unified PromptEnv for local and remote sessions

Added PromptEnv(cwd) helper that returns PRIME_CWD, PRIME_PLATFORM,
PRIME_IS_GIT_REPO. All callers of BuildRuntime now pass these.
prime script is now a pure template renderer with no detection logic.
Removed ad-hoc PRIME_CWD injection from prompt_resolver.

pkg/agent/commands.go

@@ -175,7 +175,9 @@ func (s *agent) handleCommand(ctx context.Context, input string) bool {
 				return
 			}
 			d := s.newDispatcher()
-			rt := BuildRuntime(cfg, d, s.cwd, []string{"OLLIE_SESSION_ID=" + s.sessionID, "OLLIE_UNAME=" + s.uname, "PWD=" + s.cwd})
+			env := []string{"OLLIE_SESSION_ID=" + s.sessionID, "OLLIE_UNAME=" + s.uname}
+			env = append(env, PromptEnv(s.cwd)...)
+			rt := BuildRuntime(cfg, d, s.cwd, env)
 			if rt.CfgBackend != "" {
 				newBe, err := s.newBackend(rt.CfgBackend)
 				if err != nil {

pkg/agent/prompt_resolver.go

@@ -7,12 +7,32 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"time"
 
 	"ollie/pkg/config"
 )
 
+// PromptEnv returns the standard PRIME_* environment variables for prompt
+// template resolution. For local sessions, values are detected from the
+// filesystem. For remote sessions, callers should override these with
+// values from remote.HostInfo.
+func PromptEnv(cwd string) []string {
+	platform := runtime.GOOS
+	isGitRepo := "false"
+	if cwd != "" {
+		if _, err := os.Stat(filepath.Join(cwd, ".git")); err == nil {
+			isGitRepo = "true"
+		}
+	}
+	return []string{
+		"PRIME_CWD=" + cwd,
+		"PRIME_PLATFORM=" + platform,
+		"PRIME_IS_GIT_REPO=" + isGitRepo,
+	}
+}
+
 // resolvePrompt interprets a Prompt from an agent config.
 //
 // If the prompt was parsed from a JSON array, each element is executed as a
@@ -46,10 +66,6 @@ func resolveExecPrompt(cmds []string, cwd string, env []string) (string, error)
 		if cwd != "" {
 			if info, err := os.Stat(cwd); err == nil && info.IsDir() {
 				cmd.Dir = cwd
-			} else {
-				// CWD doesn't exist locally (remote session). Inject PWD so
-				// scripts that use ${PWD} via envsubst see the correct value.
-				env = append(env, "PWD="+cwd)
 			}
 		}
 		cmd.Env = append(os.Environ(), env...)