Add instruction recommendation feature via session menu, repo menu, and /instructions command

[Copilot]

Adds the ability to ask the AI to analyze a project and recommend improvements to copilot instructions, skills, and agent definitions.

Entry points

• Session 3-dot menu → "💡 Recommend Instructions"
• Repo group context menu → "💡 Recommend Instructions"
• Slash command → /instructions

Implementation

• InstructionRecommendationHelper — Builds a context-aware prompt that includes discovered existing skills/agents so the AI suggests improvements rather than duplicates
• CopilotService.OnInstructionRecommendationRequested — Event bridge between sidebar and dashboard (sibling components communicate via service events)
• SessionListItem.razor / SessionSidebar.razor — Menu items wired through EventCallback → CopilotService.RequestInstructionRecommendation()
• Dashboard.razor — Handles the event, resolves target session, gathers project context (working directory, repo info, existing skills/agents), and sends the prompt

The prompt asks the AI to recommend concrete file contents for .github/copilot-instructions.md, skills (SKILL.md with frontmatter), and agent definitions scoped to the project's structure and patterns.

Tests

9 unit tests covering BuildRecommendationPrompt — parameter combinations, empty/null handling, skill/agent listing with and without descriptions.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[PureWeen]

🔍 R1 Review — PR #115 (Add instruction recommendation feature)

Reviewer: PP PR REVIEWER-worker-5 (3-model consensus)
Models: Claude Opus 4.6 · Claude Sonnet 4.6 · GPT-5.3-Codex
CI: No checks configured
Prior reviews: None

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Consensus Findings

#	Finding	Severity	Models
1	Duplicate /instructions message in chat history	🔴 CRITICAL	2/3 (Opus + Codex)
2	Synchronous disk I/O on Blazor UI thread	🟡 MODERATE	3/3 (all)
3	Fire-and-forget SendPromptAsync without error handling	🟡 MODERATE	3/3 (all)
4	Repo menu may target unrelated session	🟡 MODERATE	2/3 (Sonnet + Codex)

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Finding Details

1. 🔴 CRITICAL — Duplicate /instructions message in chat history

File: Dashboard.razor — HandleSlashCommand + SendInstructionRecommendation

HandleSlashCommand adds the user message for ALL slash commands before the switch statement:

session.History.Add(ChatMessage.UserMessage(input));  // runs for all commands

Then case "instructions" calls SendInstructionRecommendation, which adds another:

session.History.Add(ChatMessage.UserMessage("/instructions"));

Result: duplicate /instructions entry in chat history via the slash command path. Additionally, SendPromptAsync may also add a user message internally, potentially creating a triple entry.

Furthermore, if the session is already processing (IsProcessing), the history entry is added but SendPromptAsync may fail silently — leaving an orphaned ghost message with no response.

Fix: Remove the session.History.Add from SendInstructionRecommendation, or add a bool addToHistory = true parameter and pass false from HandleSlashCommand. Also add an IsProcessing guard at the top.

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2. 🟡 MODERATE — Synchronous disk I/O on UI thread

File: Dashboard.razor — SendInstructionRecommendation, lines calling DiscoverAvailableSkills/DiscoverAvailableAgents

Both methods perform blocking Directory.GetDirectories + File.ReadAllText (scanning .claude/skills/, .copilot/skills/, .github/skills/, ~/.copilot/installed-plugins/*/skills/, etc.). This runs on the Blazor UI synchronization context, freezing rendering during the scan.

Fix: Wrap in await Task.Run(() => { ... }):

var (skills, agents) = await Task.Run(() => (
    CopilotService.DiscoverAvailableSkills(workingDirectory)
        .Select(s => (s.Name, s.Description)).ToList(),
    CopilotService.DiscoverAvailableAgents(workingDirectory)
        .Select(a => (a.Name, a.Description)).ToList()
));

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3. 🟡 MODERATE — Fire-and-forget without error handling

File: Dashboard.razor — SendInstructionRecommendation

_ = CopilotService.SendPromptAsync(targetSession, prompt);

Every other significant send site in Dashboard.razor attaches a .ContinueWith() fault handler to surface errors. This bare _ = silently swallows exceptions. If the session is disposed, reconnecting, or in an error state, the user gets no feedback.

Fix: Add .ContinueWith() error handling consistent with the primary send path.

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4. 🟡 MODERATE — Repo menu targets unrelated session

File: Dashboard.razor — SendInstructionRecommendation (repo menu path)

When triggered from the repo context menu (sessionName is null, only repoId provided), the code falls back to expandedSession or sessions[0] — neither guaranteed to be associated with the given repo. The skill/agent discovery uses the repo's worktree path, but the prompt is sent to a session that may be working in a completely different repository. The AI gets contradictory context.

Additionally, RepoManager.Worktrees.FirstOrDefault(w => w.RepoId == repoId) is non-deterministic when multiple worktrees exist for the same repo.

Fix: Use WorktreeInfo.SessionName to find the session associated with this repo's worktree, or create a new session scoped to the repo.

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Non-consensus observations (1/3, informational)

• Sonnet flagged prompt injection via skill/agent names — malicious SKILL.md descriptions could inject into the LLM prompt. Low practical risk since the prompt targets the same AI that already has access to those files, but worth noting.
• Sonnet flagged sessions[0] fallback as surprising UX (silently hijacks session focus)
• Opus noted redundant TOCTOU double-scan in session resolution (Any then FirstOrDefault)

What's clean ✅

• Event subscribe/unsubscribe correctly paired in OnInitializedAsync and DisposeAsync
• Thread marshaling via InvokeAsync in HandleInstructionRecommendation is correct
• InstructionRecommendationHelper is well-structured static class with good test coverage (9 tests)
• RepoManager injection is valid (already registered as a service)
• Compile Include link correctly added to test csproj

Test coverage assessment

The 9 InstructionRecommendationHelperTests cover the prompt builder well. Missing: tests for the duplicate-message bug, session resolution edge cases, IsProcessing guard, and error paths in SendInstructionRecommendation.

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Recommended Action: ⚠️ Request Changes

1. Fix duplicate history entry (Critical) — the /instructions slash command path double-adds the user message
2. Offload disk I/O to Task.Run for DiscoverAvailableSkills/DiscoverAvailableAgents
3. Add error handling to the fire-and-forget SendPromptAsync call
4. Fix repo-menu session targeting to prefer sessions associated with the repo's worktree