build(test-streamlit): Migrate from pip to uv

[ericapisani]

Summary

• Replace requirements.txt with pyproject.toml for dependency management
• Update run.sh to use uv run instead of manual venv/pip workflow
• Part of PY-2428 migration effort

Test plan

• Run ./run.sh and verify the streamlit app starts correctly

🤖 Generated with Claude Code

[linear-code]

PY-2477

PY-2428

[sentry]

Bug: The script uses uv immediately after installation without updating the PATH, causing a 'command not found' error in environments where ~/.local/bin is not on the PATH.
_{Severity: HIGH}

Suggested Fix

After the uv installation command, source the environment file to update the PATH for the current session. Add source "$HOME/.local/bin/env" before the uv run command to ensure the uv binary is found.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: test-streamlit/run.sh#L4-L8

Potential issue: The script installs `uv` via `curl | sh` but then immediately attempts
to execute it in the same shell session. The installer modifies shell profile files to
add `uv` to the `PATH`, but these changes are not applied to the currently-running
script. On systems where `~/.local/bin` is not already in the `PATH`, such as minimal CI
environments or fresh macOS systems, the `uv` command will not be found. Since the
script uses `set -euo pipefail`, this will cause the script to fail with a 'command not
found' error and exit immediately.

_{Did we get this right? 👍 / 👎 to inform future reviews.}