docs: clarify all PR template sections are required, not just thinking path

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/PULL_REQUEST_TEMPLATE.md

@@ -38,9 +38,25 @@
 
 -
 
+## Model Used
+
+<!--
+  Required. Specify which AI model was used to produce or assist with
+  this change. Be as descriptive as possible — include:
+    • Provider and model name (e.g., Claude, GPT, Gemini, Codex)
+    • Exact model ID or version (e.g., claude-opus-4-6, gpt-4-turbo-2024-04-09)
+    • Context window size if relevant (e.g., 1M context)
+    • Reasoning/thinking mode if applicable (e.g., extended thinking, chain-of-thought)
+    • Any other relevant capability details (e.g., tool use, code execution)
+  If no AI model was used, write "None — human-authored".
+-->
+
+-
+
 ## Checklist
 
 - [ ] I have included a thinking path that traces from project context to this change
+- [ ] I have specified the model used (with version and capability details)
 - [ ] I have run tests locally and they pass
 - [ ] I have added or updated tests where applicable
 - [ ] If this change affects the UI, I have included before/after screenshots

CONTRIBUTING.md

@@ -11,8 +11,9 @@ We really appreciate both small fixes and thoughtful larger changes.
 - Pick **one** clear thing to fix/improve
 - Touch the **smallest possible number of files**
 - Make sure the change is very targeted and easy to review
-- All automated checks pass (including Greptile comments)
+- All tests pass and CI is green
-- No new lint/test failures
+- Greptile score is 5/5 with all comments addressed
+- Use the [PR template](.github/PULL_REQUEST_TEMPLATE.md)
 
 These almost always get merged quickly when they're clean.
 
@@ -26,11 +27,26 @@ These almost always get merged quickly when they're clean.
   - Before / After screenshots (or short video if UI/behavior change)
   - Clear description of what & why
   - Proof it works (manual testing notes)
-  - All tests passing
+  - All tests passing and CI green
-  - All Greptile + other PR comments addressed
+  - Greptile score 5/5 with all comments addressed
+  - [PR template](.github/PULL_REQUEST_TEMPLATE.md) fully filled out
 
 PRs that follow this path are **much** more likely to be accepted, even when they're large.
 
+## PR Requirements (all PRs)
+
+### Use the PR Template
+
+Every pull request **must** follow the PR template at [`.github/PULL_REQUEST_TEMPLATE.md`](.github/PULL_REQUEST_TEMPLATE.md). If you create a PR via the GitHub API or other tooling that bypasses the template, copy its contents into your PR description manually. The template includes required sections: Thinking Path, What Changed, Verification, Risks, and a Checklist.
+
+### Tests Must Pass
+
+All tests must pass before a PR can be merged. Run them locally first and verify CI is green after pushing.
+
+### Greptile Review
+
+We use [Greptile](https://greptile.com) for automated code review. Your PR must achieve a **5/5 Greptile score** with **all Greptile comments addressed** before it can be merged. If Greptile leaves comments, fix or respond to each one and request a re-review.
+
 ## General Rules (both paths)
 
 - Write clear commit messages
@@ -41,7 +57,7 @@ PRs that follow this path are **much** more likely to be accepted, even when the
 
 ## Writing a Good PR message
 
-Please include a "thinking path" at the top of your PR message that explains from the top of the project down to what you fixed. E.g.:
+Your PR description must follow the [PR template](.github/PULL_REQUEST_TEMPLATE.md). All sections are required. The "thinking path" at the top explains from the top of the project down to what you fixed. E.g.:
 
 ### Thinking Path Example 1:
 

server/src/__tests__/workspace-runtime.test.ts

@@ -24,6 +24,7 @@ import {
   realizeExecutionWorkspace,
   releaseRuntimeServicesForRun,
   resetRuntimeServicesForTests,
+  resolveShell,
   sanitizeRuntimeServiceBaseEnv,
   stopRuntimeServicesForExecutionWorkspace,
   type RealizedExecutionWorkspace,
@@ -1345,6 +1346,60 @@ describe("ensureRuntimeServicesForRun", () => {
   });
 });
 
+describe("resolveShell (shell fallback)", () => {
+  const originalShell = process.env.SHELL;
+  const originalPlatform = process.platform;
+
+  afterEach(() => {
+    if (originalShell !== undefined) {
+      process.env.SHELL = originalShell;
+    } else {
+      delete process.env.SHELL;
+    }
+    Object.defineProperty(process, "platform", { value: originalPlatform });
+  });
+
+  it("returns process.env.SHELL when set", () => {
+    process.env.SHELL = "/usr/bin/zsh";
+    expect(resolveShell()).toBe("/usr/bin/zsh");
+  });
+
+  it("trims whitespace from SHELL env var", () => {
+    process.env.SHELL = "  /usr/bin/fish  ";
+    expect(resolveShell()).toBe("/usr/bin/fish");
+  });
+
+  it("falls back to /bin/sh on non-Windows when SHELL is unset", () => {
+    delete process.env.SHELL;
+    Object.defineProperty(process, "platform", { value: "linux" });
+    expect(resolveShell()).toBe("/bin/sh");
+  });
+
+  it("falls back to sh (bare) on Windows when SHELL is unset", () => {
+    delete process.env.SHELL;
+    Object.defineProperty(process, "platform", { value: "win32" });
+    expect(resolveShell()).toBe("sh");
+  });
+
+  it("falls back to /bin/sh on darwin when SHELL is unset", () => {
+    delete process.env.SHELL;
+    Object.defineProperty(process, "platform", { value: "darwin" });
+    expect(resolveShell()).toBe("/bin/sh");
+  });
+
+  it("treats empty SHELL as unset and uses platform fallback", () => {
+    process.env.SHELL = "";
+    Object.defineProperty(process, "platform", { value: "linux" });
+    expect(resolveShell()).toBe("/bin/sh");
+  });
+
+  it("treats whitespace-only SHELL as unset and uses platform fallback", () => {
+    process.env.SHELL = "   ";
+    Object.defineProperty(process, "platform", { value: "win32" });
+    expect(resolveShell()).toBe("sh");
+  });
+});
+
 describeEmbeddedPostgres("workspace runtime startup reconciliation", () => {
   let db!: ReturnType<typeof createDb>;
   let tempDb: Awaited<ReturnType<typeof startEmbeddedPostgresTestDatabase>> | null = null;

server/src/services/workspace-runtime.ts

@@ -24,6 +24,10 @@ import type { WorkspaceOperationRecorder } from "./workspace-operations.js";
 import { readExecutionWorkspaceConfig } from "./execution-workspaces.js";
 import { readProjectWorkspaceRuntimeConfig } from "./project-workspace-runtime-config.js";
 
+export function resolveShell(): string {
+  return process.env.SHELL?.trim() || (process.platform === "win32" ? "sh" : "/bin/sh");
+}
+
 export interface ExecutionWorkspaceInput {
   baseCwd: string;
   source: "project_primary" | "task_session" | "agent_home";
@@ -379,7 +383,7 @@ async function runWorkspaceCommand(input: {
   env: NodeJS.ProcessEnv;
   label: string;
 }) {
-  const shell = process.env.SHELL?.trim() || "/bin/sh";
+  const shell = resolveShell();
   const proc = await executeProcess({
     command: shell,
     args: ["-c", input.command],
@@ -475,7 +479,7 @@ async function recordWorkspaceCommandOperation(
     cwd: input.cwd,
     metadata: input.metadata ?? null,
     run: async () => {
-      const shell = process.env.SHELL?.trim() || "/bin/sh";
+      const shell = resolveShell();
       const result = await executeProcess({
         command: shell,
         args: ["-c", input.command],
@@ -1285,6 +1289,7 @@ async function startLocalRuntimeService(input: {
     const portEnvKey = asString(portConfig.envKey, "PORT");
     env[portEnvKey] = String(port);
   }
+
   const expose = parseObject(input.service.expose);
   const readiness = parseObject(input.service.readiness);
   const urlTemplate =
@@ -1359,7 +1364,8 @@ async function startLocalRuntimeService(input: {
       );
     }
   }
-  const shell = process.env.SHELL?.trim() || "/bin/sh";
+  
+  const shell = resolveShell();
   const child = spawn(shell, ["-lc", command], {
     cwd: serviceCwd,
     env,