Extract CopilotChat and CopilotCli adapters (#654)

Move VS Code Copilot Chat and Copilot CLI session discovery out of the monolithic sessionDiscovery.ts and into proper adapters under src/adapters/, mirroring the existing 7 adapters.

- Add CopilotChatAdapter: workspaceStorage chatSessions (3 layouts), globalStorage emptyWindowChatSessions, globalStorage {GitHub,github}.copilot-chat recursive scan, WSL Windows-side paths

- Add CopilotCliAdapter: ~/.copilot/session-state flat .json/.jsonl + UUID subdir events.jsonl

- Strip sessionDiscovery.ts to a thin generic adapter loop with dedup by normalized path

- Wire both adapters into extension.ts and cli/src/helpers.ts (registered last so more-specific adapters win)

- handles() returns false intentionally so the existing fallback parser keeps owning per-session parsing for these editors. Predicates (isCopilotChatSessionPath / isCopilotCliSessionPath) and helpers are exported for the planned follow-up that flips handles().

- Add 31 new unit tests across copilotChatAdapter.test.ts and copilotCliAdapter.test.ts

- Update ecosystemAdapters.test.ts to expect 9 adapters

- Update .github/instructions/{cli,vscode-extension}.instructions.md

Tests: 961 pass, 0 fail, 3 skipped (was 935 before).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: rajbos

.github/instructions/cli.instructions.md

@@ -31,6 +31,8 @@ Or from the repo root:
 
 When adding support for a new editor or data source, wire it into **both** `vscode-extension/src/` (see `.github/instructions/vscode-extension.instructions.md`) **and** this CLI.
 
+> **Adapter architecture (issue #654)**: The CLI shares the adapter classes from `vscode-extension/src/adapters/` and registers them in `_ecosystems` inside `cli/src/helpers.ts`. Currently 9 adapters are registered: OpenCode, Crush, Continue, ClaudeCode, ClaudeDesktop, VisualStudio, MistralVibe, **CopilotChat**, **CopilotCli**. The Copilot adapters own discovery but their `handles()` returns `false`, so `processSessionFile()` falls through to the existing per-format helpers (JSONL/JSON parsing) for those files. Order matters — register Copilot adapters **last**.
+
 ### CLI Files to Update
 
 | File | What to add |

.github/instructions/vscode-extension.instructions.md

@@ -151,3 +151,17 @@ To maintain a consistent, VS Code-native look across all webview panels (Details
 ## Adding a New Editor / Data Source
 
 When adding support for a new editor or data source, you must wire it into **both** this extension (`vscode-extension/src/`) **and** the CLI (`cli/src/`). See `.github/instructions/cli.instructions.md` for the CLI integration checklist.
+
+### Adapter architecture (issue #654)
+
+All editor integrations live as adapters under `vscode-extension/src/adapters/` implementing `IEcosystemAdapter` (and `IDiscoverableEcosystem` when discovery is needed). `sessionDiscovery.ts` is intentionally a thin generic loop: it iterates the adapters registered in `extension.ts` (`this.ecosystems`) and dedupes the resulting paths. There are **no hardcoded editor paths in `sessionDiscovery.ts`**.
+
+Current adapter set (9):
+- `OpenCodeAdapter`, `CrushAdapter`, `ContinueAdapter`, `ClaudeCodeAdapter`, `ClaudeDesktopAdapter`, `VisualStudioAdapter`, `MistralVibeAdapter`
+- `CopilotChatAdapter` — VS Code Copilot Chat (workspaceStorage chatSessions in 3 layouts, globalStorage emptyWindowChatSessions, globalStorage `{GitHub,github}.copilot-chat` recursive scan, WSL Windows-side paths)
+- `CopilotCliAdapter` — `~/.copilot/session-state/` flat `.json`/`.jsonl` plus UUID subdirs with `events.jsonl`
+
+**Adapter ordering matters**: register more-specific adapters first. `CopilotChatAdapter` and `CopilotCliAdapter` are registered **last** in `this.ecosystems`.
+
+**`handles()` for CopilotChat/Cli currently returns `false`**: discovery is owned by the adapters, but per-session parsing is still routed through the existing fallback path in `extension.ts` (`countInteractionsInSession`, `estimateTokensFromSession`, `getSessionFileDataCached`). A future PR can flip `handles()` to use the exported `isCopilotChatSessionPath` / `isCopilotCliSessionPath` predicates once the JSON parser helpers are extracted from `extension.ts`. When you flip `handles()`, also fix `_detectEditorSource(filePath, (p) => !!this.findEcosystem(p))` at extension.ts:~3224 — the predicate must check `?.id === 'opencode'` (or use `getEditorTypeFromPath` convention) so that VS Code paths are still labeled "VS Code", not "OpenCode".
+

cli/src/helpers.ts

@@ -15,7 +15,7 @@ import { ClaudeCodeDataAccess } from '../../vscode-extension/src/claudecode';
 import { ClaudeDesktopCoworkDataAccess } from '../../vscode-extension/src/claudedesktop';
 import { MistralVibeDataAccess } from '../../vscode-extension/src/mistralvibe';
 import type { IEcosystemAdapter } from '../../vscode-extension/src/ecosystemAdapter';
-import { OpenCodeAdapter, CrushAdapter, ContinueAdapter, ClaudeDesktopAdapter, ClaudeCodeAdapter, VisualStudioAdapter, MistralVibeAdapter } from '../../vscode-extension/src/adapters';
+import { OpenCodeAdapter, CrushAdapter, ContinueAdapter, ClaudeDesktopAdapter, ClaudeCodeAdapter, VisualStudioAdapter, MistralVibeAdapter, CopilotChatAdapter, CopilotCliAdapter } from '../../vscode-extension/src/adapters';
 import { parseSessionFileContent } from '../../vscode-extension/src/sessionParser';
 import { estimateTokensFromText, getModelFromRequest, isJsonlContent, estimateTokensFromJsonlSession, calculateEstimatedCost, getModelTier } from '../../vscode-extension/src/tokenEstimation';
 import type { DetailedStats, PeriodStats, ModelUsage, EditorUsage, SessionFileCache, UsageAnalysisStats, UsageAnalysisPeriod } from '../../vscode-extension/src/types';
@@ -98,6 +98,11 @@ const _ecosystems: IEcosystemAdapter[] = [
 	new ClaudeDesktopAdapter(_claudeDesktopCoworkInstance),
 	new ClaudeCodeAdapter(_claudeCodeInstance),
 	new MistralVibeAdapter(_mistralVibeInstance),
+	// Copilot Chat / CLI adapters: discovery-only. Their handles() returns
+	// false so processSessionFile() falls through to the shared parser path
+	// for VS Code Copilot Chat and CLI files. See issue #654.
+	new CopilotChatAdapter(),
+	new CopilotCliAdapter(),
 ];
 
 /** Create session discovery instance for CLI */