Fix/dotfiles fish compatibility (#682)

## Description

The dotfiles module does not work when using non-POSIX shells i.e. Fish.

## Type of Change

- [ ] New module
- [ ] New template
- [x] Bug fix
- [x] Feature/enhancement
- [ ] Documentation
- [ ] Other

## Module Information

**Path:** `registry/coder/modules/dotfiles`  
**New version:** `v1.4.1`  
**Breaking change:** [ ] Yes [ ] No

## Testing & Validation

- [x] Tests pass (`bun test`)
- [x] Code formatted (`bun fmt`)
- [x] Changes tested locally

```
bun test v1.3.8 (b64edcb4)

registry/coder/modules/dotfiles/main.test.ts:
✓ dotfiles > required variables [190.40ms]
✓ dotfiles > missing variable: agent_id [43.12ms]
✓ dotfiles > default output [150.15ms]
✓ dotfiles > set a default dotfiles_uri [159.14ms]
✓ dotfiles > command uses bash for fish shell compatibility [164.08ms]
✓ dotfiles > set custom order for coder_parameter [166.50ms]

 6 pass
 0 fail
 7 expect() calls
Ran 6 tests across 1 file. [1184.00ms]
```

I tested this with a new workspace on Coder v2.27.3 with fish, zsh, and
bash.

---------

Co-authored-by: DevCats <christofer@coder.com>
Co-authored-by: blink-so[bot] <211532188+blink-so[bot]@users.noreply.github.com>

Author: 3 people

registry/coder/modules/dotfiles/README.md

@@ -18,7 +18,7 @@ Under the hood, this module uses the [coder dotfiles](https://coder.com/docs/v2/
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.4.0"
+  version  = "1.4.1"
   agent_id = coder_agent.example.id
 }
 ```
@@ -31,7 +31,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.4.0"
+  version  = "1.4.1"
   agent_id = coder_agent.example.id
 }
 ```
@@ -42,7 +42,7 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.4.0"
+  version  = "1.4.1"
   agent_id = coder_agent.example.id
   user     = "root"
 }
@@ -54,14 +54,14 @@ module "dotfiles" {
 module "dotfiles" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/dotfiles/coder"
-  version  = "1.4.0"
+  version  = "1.4.1"
   agent_id = coder_agent.example.id
 }
 
 module "dotfiles-root" {
   count        = data.coder_workspace.me.start_count
   source       = "registry.coder.com/coder/dotfiles/coder"
-  version      = "1.4.0"
+  version      = "1.4.1"
   agent_id     = coder_agent.example.id
   user         = "root"
   dotfiles_uri = module.dotfiles.dotfiles_uri
@@ -90,7 +90,7 @@ You can set a default dotfiles repository for all users by setting the `default_
 module "dotfiles" {
   count                = data.coder_workspace.me.start_count
   source               = "registry.coder.com/coder/dotfiles/coder"
-  version              = "1.4.0"
+  version              = "1.4.1"
   agent_id             = coder_agent.example.id
   default_dotfiles_uri = "https://github.com/coder/dotfiles"
 }

registry/coder/modules/dotfiles/main.test.ts

@@ -56,6 +56,21 @@ describe("dotfiles", async () => {
     }
   });
 
+  it("command uses bash for fish shell compatibility", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      manual_update: "true",
+      dotfiles_uri: "https://github.com/test/dotfiles",
+    });
+
+    const app = state.resources.find(
+      (r) => r.type === "coder_app" && r.name === "dotfiles",
+    );
+
+    expect(app).toBeDefined();
+    expect(app?.instances[0]?.attributes?.command).toContain("/bin/bash -c");
+  });
+
   it("set custom order for coder_parameter", async () => {
     const order = 99;
     const state = await runTerraformApply(import.meta.dir, {

registry/coder/modules/dotfiles/main.tf

@@ -164,12 +164,12 @@ resource "coder_app" "dotfiles" {
   icon         = "/icon/dotfiles.svg"
   order        = var.order
   group        = var.group
-  command = templatefile("${path.module}/run.sh", {
+  command = "/bin/bash -c \"$(echo ${base64encode(templatefile("${path.module}/run.sh", {
     DOTFILES_URI : local.dotfiles_uri,
     DOTFILES_USER : local.user,
     DOTFILES_BRANCH : local.dotfiles_branch,
     POST_CLONE_SCRIPT : local.encoded_post_clone_script
-  })
+  }))} | base64 -d)\""
 }
 
 output "dotfiles_uri" {