Add standalone R data analysis lab exercise

[Copilot]

R developers had no dedicated lab — the existing exercises are built around a Todo app in JS/Python/C#, which doesn't map to typical R workflows.

Changes

New lab: labs/r-data-analysis.md

Self-contained lab covering the full Copilot feature set through a data analysis lens:

• Inline completion — data loading, date parsing, dplyr transformations, ggplot2 charts, NES pattern recognition
• Chat / Ask Mode — statistical summaries, /explain / /fix / /doc / /tests slash commands, #file and @workspace context
• Agent Mode — scaffold a complete analysis report script end-to-end
• Challenges: sales rep dashboard, IQR outlier detection, time-series forecasting

New starter code: starter-code/r/

r/
├── README.md                  # setup + package install instructions
├── data/sample_sales.csv      # 40-row fictional sales dataset (date, region, product,
│                              # category, units_sold, unit_price, discount, sales_rep)
└── src/
    ├── analysis.R             # main entry point with exercise stubs
    ├── data_processor.R       # cleaning/transformation function stubs
    └── visualizer.R           # ggplot2 visualization function stubs

Stub files use comments as Copilot prompts — consistent with the pattern used in Python/JS starter code.

README.md

• Added R (R 4.2+) to the language prerequisites table with a link to the new lab
• Updated the project structure tree and added an "R Track" section to the workshop outline

Original prompt

Start implementation

[Chronological Review: The conversation began with the user requesting the creation of a separate lab exercise using R code, specifically focused on real use cases related to the use of Copilot. The user emphasized that this exercise should be distinct from existing ones and tailored for developers who only use R. The user then prompted for the implementation to start, indicating readiness to proceed with the task.]

[Intent Mapping:

1. "I want to create a separate lab exercise that uses R code instead." - User's request for a new lab exercise.
2. "Make sure to make it separate from the other exercises." - User's emphasis on the distinct nature of the new exercise.
3. "Start implementation." - User's directive to begin the actual work on the lab exercise.]

[Technical Inventory:

• Language: R - The user specified that the lab exercises should be developed using R.
• Focus: Copilot - The exercises should relate to the use of Copilot, similar to existing exercises.]

[Code Archaeology: No specific files or code changes have been discussed or modified yet, as the conversation is still in the planning phase.]

[Progress Assessment:

• Completed Tasks: None yet, as the conversation has focused on planning and initiating the task.
• Partially Complete Work: The request for the lab exercise is clear, but implementation has not yet started.]

[Context Validation: All necessary context for continuing the work on the R lab exercise is captured, including the focus on real use cases and the requirement for separation from existing exercises.]

[Recent Commands Analysis:

• Last Agent Commands: The user requested to "Start implementation."
• Tool Results Summary: No tool results were generated as the conversation was primarily focused on planning and initiating the task.
• Pre-Summary State: The agent was preparing to begin the implementation of the R lab exercise when the token budget was exceeded.
• Operation Context: The commands executed were directly related to the user's goal of creating a new lab exercise using R code, emphasizing the need for practical applications and distinctiveness from previous exercises.]

1. Conversation Overview: - Primary Objectives: "I want to create a separate lab exercise that uses R code instead." and "Make sure to make it separate from the other exercises." - Session Context: The user initiated a request for a new lab exercise focused on R and Copilot, followed by a prompt to start implementation. - User Intent Evolution: The user clearly defined the need for a distinct lab exercise and expressed readiness to begin the implementation.

2. Technical Foundation:

• R: The programming language specified for the lab exercises, focusing on real use cases.
• Copilot: The context in which the exercises should be framed, similar to existing exercises.

3. Codebase Status:

• No specific files or code changes have been discussed yet, as the conversation is still in the planning phase.

4. Problem Resolution:

• Issues Encountered: None at this stage, as the conversation has not progressed to implementation.
• Solutions Implemented: Not applicable yet.
• Debugging Context: No ongoing troubleshooting efforts have been mentioned.
• Lessons Learned: Not applicable yet.

5. Progress Tracking:

• Completed Tasks: None completed; the focus has been on planning.
• Partially Complete Work: The request for the lab exercise is clear, but implementation has not yet started.

6. Active Work State:

• Current Focus: The user is focused on creating a new lab exercise using R code.
• Recent Context: The last exchanges involved the user requesting to start the implementation of the lab exercise.
• Working Code: No code snippets have been discussed yet.
• Immediate Context: The user was ready to begin the implementation of the R lab exercise.

7. Recent Operations:

• Last Agent Commands: "Start implementation."
• Tool Results Summary: No tool results were generated as the conversation was focused on planning.
• Pre-Summary State: The agent was preparing to begin the implementation of the R lab exercise.
• Operation Context: The commands executed were directly related to the user's goal of creating a new lab exercise using R code.

8. Continuation Plan:

• [Pending Task 1]: Begin the implementation of the R lab exercise with a focus on real use cases.
• [Pending Task 2]: Ensure the exercise is distinct from existing ones, as specified by the user.
• [Priority Information]: The immediate next step is to start the implementation of the lab exercise.
• [Next Action]: Proceed with the implementation of the R lab exercise as requested by the user.

Created from VS Code.