feat(coding-agent): ResourceLoader, package management, and /reload command (#645)

- Add ResourceLoader interface and DefaultResourceLoader implementation
- Add PackageManager for npm/git extension sources with install/remove/update
- Add session.reload() and session.bindExtensions() APIs
- Add /reload command in interactive mode
- Add CLI flags: --skill, --theme, --prompt-template, --no-themes, --no-prompt-templates
- Add pi install/remove/update commands for extension management
- Refactor settings.json to use arrays for skills, prompts, themes
- Remove legacy SkillsSettings source flags and filters
- Update SDK examples and documentation for ResourceLoader pattern
- Add theme registration and loadThemeFromPath for dynamic themes
- Add getShellEnv to include bin dir in PATH for bash commands

packages/coding-agent/src/utils/shell.ts

@@ -1,6 +1,8 @@
 import { existsSync } from "node:fs";
+import { delimiter } from "node:path";
 import { spawn, spawnSync } from "child_process";
 import { getSettingsPath } from "../config.js";
+import { getBinDir } from "../config.js";
 import { SettingsManager } from "../core/settings-manager.js";
 
 let cachedShellConfig: { shell: string; args: string[] } | null = null;
@@ -95,6 +97,20 @@ export function getShellConfig(): { shell: string; args: string[] } {
 	return cachedShellConfig;
 }
 
+export function getShellEnv(): NodeJS.ProcessEnv {
+	const binDir = getBinDir();
+	const pathKey = Object.keys(process.env).find((key) => key.toLowerCase() === "path") ?? "PATH";
+	const currentPath = process.env[pathKey] ?? "";
+	const pathEntries = currentPath.split(delimiter).filter(Boolean);
+	const hasBinDir = pathEntries.includes(binDir);
+	const updatedPath = hasBinDir ? currentPath : [binDir, currentPath].filter(Boolean).join(delimiter);
+
+	return {
+		...process.env,
+		[pathKey]: updatedPath,
+	};
+}
+
 /**
  * Sanitize binary output for display/storage.
  * Removes characters that crash string-width or cause display issues: