feat: integrate claude-code-base-action as local subaction (#285)

* feat: integrate claude-code-base-action as local subaction

- Copy claude-code-base-action into base-action/ directory
- Update action.yml to reference ./base-action instead of external repo
- Preserve complete base action structure for future refactoring

This eliminates the external dependency while maintaining modularity.

* feat: consolidate CI workflows and add version bump workflow

- Move base-action test workflows to main .github/workflows/
- Update workflow references to use ./base-action
- Add CI jobs for base-action (test, typecheck, prettier)
- Add bump-claude-code-version workflow for base-action
- Remove redundant .github directory from base-action

This consolidates all CI workflows in one place while maintaining
full test coverage for both the main action and base-action.

* tsc

* copy again

* fix tests

* fix: use absolute path for base-action reference

Replace relative path ./base-action with ${{ github.action_path }}/base-action
to ensure the action works correctly when used in other repositories.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

* fix: inline base-action execution to support usage in other repos

Replace uses: ./base-action with direct shell execution since GitHub Actions
doesn't support dynamic paths in composite actions. This ensures the action
works correctly when used in other repositories.

Changes:
- Install Claude Code globally before execution
- Run base-action's index.ts directly with bun
- Pass all required INPUT_* environment variables
- Maintain base-action for future separate publishing

🤖 Generated with [Claude Code](https://claude.ai/code)

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

---------

Co-authored-by: Claude <noreply@anthropic.com>

base-action/test/prepare-prompt.test.ts

@@ -0,0 +1,114 @@
+#!/usr/bin/env bun
+
+import { describe, test, expect, beforeEach, afterEach } from "bun:test";
+import { preparePrompt, type PreparePromptInput } from "../src/prepare-prompt";
+import { unlink, writeFile, readFile, stat } from "fs/promises";
+
+describe("preparePrompt integration tests", () => {
+  beforeEach(async () => {
+    try {
+      await unlink("/tmp/claude-action/prompt.txt");
+    } catch {
+      // Ignore if file doesn't exist
+    }
+  });
+
+  afterEach(async () => {
+    try {
+      await unlink("/tmp/claude-action/prompt.txt");
+    } catch {
+      // Ignore if file doesn't exist
+    }
+  });
+
+  test("should create temporary prompt file when only prompt is provided", async () => {
+    const input: PreparePromptInput = {
+      prompt: "This is a test prompt",
+      promptFile: "",
+    };
+
+    const config = await preparePrompt(input);
+
+    expect(config.path).toBe("/tmp/claude-action/prompt.txt");
+    expect(config.type).toBe("inline");
+
+    const fileContent = await readFile(config.path, "utf-8");
+    expect(fileContent).toBe("This is a test prompt");
+
+    const fileStat = await stat(config.path);
+    expect(fileStat.size).toBeGreaterThan(0);
+  });
+
+  test("should use existing file when promptFile is provided", async () => {
+    const testFilePath = "/tmp/test-prompt.txt";
+    await writeFile(testFilePath, "Prompt from file");
+
+    const input: PreparePromptInput = {
+      prompt: "",
+      promptFile: testFilePath,
+    };
+
+    const config = await preparePrompt(input);
+
+    expect(config.path).toBe(testFilePath);
+    expect(config.type).toBe("file");
+
+    await unlink(testFilePath);
+  });
+
+  test("should fail when neither prompt nor promptFile is provided", async () => {
+    const input: PreparePromptInput = {
+      prompt: "",
+      promptFile: "",
+    };
+
+    await expect(preparePrompt(input)).rejects.toThrow(
+      "Neither 'prompt' nor 'prompt_file' was provided",
+    );
+  });
+
+  test("should fail when promptFile points to non-existent file", async () => {
+    const input: PreparePromptInput = {
+      prompt: "",
+      promptFile: "/tmp/non-existent-file.txt",
+    };
+
+    await expect(preparePrompt(input)).rejects.toThrow(
+      "Prompt file '/tmp/non-existent-file.txt' does not exist.",
+    );
+  });
+
+  test("should fail when prompt is empty", async () => {
+    const emptyFilePath = "/tmp/empty-prompt.txt";
+    await writeFile(emptyFilePath, "");
+
+    const input: PreparePromptInput = {
+      prompt: "",
+      promptFile: emptyFilePath,
+    };
+
+    await expect(preparePrompt(input)).rejects.toThrow("Prompt file is empty");
+
+    try {
+      await unlink(emptyFilePath);
+    } catch {
+      // Ignore cleanup errors
+    }
+  });
+
+  test("should fail when both prompt and promptFile are provided", async () => {
+    const testFilePath = "/tmp/test-prompt.txt";
+    await writeFile(testFilePath, "Prompt from file");
+
+    const input: PreparePromptInput = {
+      prompt: "This should cause an error",
+      promptFile: testFilePath,
+    };
+
+    await expect(preparePrompt(input)).rejects.toThrow(
+      "Both 'prompt' and 'prompt_file' were provided. Please specify only one.",
+    );
+
+    await unlink(testFilePath);
+  });
+});