Error when read non-UTF8 sourcecode file

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

macOS 15.3.2 (24D81)

### Expected behaviour

Q Developer can read or retry non-UTF8 sourcecode without errors.

### Actual behaviour

Q Developer occured the error when read non-UTF8 sourcecode.

```
Read from filesystem
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Reading directory: /Users/kensuke/Desktop/myproject/source code with maximum depth of 0

Reading from filesystem...
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Reading:

🟢 Completed in 0.2s

次に、主要なソースファイルの内容を確認して、プロジェクトの構造を理解しましょう。まずはメインファイルと思われるsource.cppを見てみます。

Read from filesystem
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Amazon Q is having trouble responding right now:
0: failed to print tool: stream did not contain valid UTF-8

Location:
crates/q_cli/src/cli/chat/mod.rs:476

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.
```

### Steps to reproduce

1. move project directory included non-UTF8 sourcecode.(Shift-JIS)
2. ask "This directory contains the server program. Please read this source code first. Then, generate a context file so that Amazon Q Developer can execute the program properly." to q chat
3. Q Developer occured the error when read non-UTF8 sourcecode.

### Environment

```yaml
[q-details]
version = "1.7.2"
hash = "b6bf5f1675dd7395009e8bc65c1145820671f211"
date = "2025-03-21T01:36:16.66764Z (16d ago)"
variant = "full"

[system-info]
os = "macOS 15.3.2 (24D81)"
chip = "Apple M2"
total-cores = 8
memory = "8.00 GB"

[environment]
cwd = "/Users/USER/Desktop/myproject/source code"
cli-path = "/Users/USER/Desktop/myproject/source code"
os = "Mac"
shell-path = "/bin/zsh"
shell-version = "5.9"
terminal = "macOS"
install-method = "unknown"

[env-vars]
PATH = "/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Library/Apple/usr/bin:/Users/USER/.local/bin"
QTERM_SESSION_ID = "b4d44d9a3a4e4e248117563bd71e799c"
Q_SET_PARENT_CHECK = "1"
Q_TERM = "1.7.2"
SHELL = "/bin/zsh"
TERM = "xterm-256color"
__CFBundleIdentifier = "com.apple.Terminal"
```