docs(readme): mark Copilot CLI usage/sessions/dashboard as supported (#766)

[ousamabenyounes]

Summary

PR #666 ("feat: add privacy-safe Copilot telemetry") shipped GitHub Copilot CLI support for the three Team Improvement columns — usage, sessions, and dashboard — but the support matrix in the README files still showed em-dashes (—) for those cells. This is documentation drift: the matrix contradicts the shipped, tested behavior. This PR flips the three Copilot CLI cells from — to ✓ in all five README language variants. No code changes.

Type of Change

• Documentation only

Evidence per column (verified on current main)

• usage — Copilot token usage/fallback is read in src/dashboard-collector.ts (Copilot usage tail/scan constants, isCopilot token handling) with the missing-token fallback covered by tests; src/usage-tracker.ts resolves the Copilot home.
• sessions — Copilot session lifecycle is wired via COPILOT_SESSION_END_SPEC in src/builtin-hooks.ts (Copilot additionally gets SessionEnd) and the session_end/isCopilot path in src/dashboard-collector.ts; path-free session IDs enforced in src/utils/session-id.ts.
• dashboard — Copilot session/lifecycle events feed the local dashboard in src/dashboard-collector.ts (isCopilot event handling, token snapshots). docs/usage-guide.md already documents this: "Session IDs, skill usage, prompt counts, lifecycle state, and final token totals feed the local dashboard."

Five languages

README.md, README.zh-CN.md, README.ja.md, README.ko.md, README.th.md — one identical cell change each (—→✓ on the Copilot CLI row), matrices remain structurally identical.

Test Plan

• npx tsc --noEmit passes
• npx vitest run on the Copilot telemetry suites passes: dashboard-collector (144), usage-tracking (93), session-id (9), builtin-hooks (7), copilot-adapter (16), hook-dispatch-cli (18) — 287 tests, all green.
• Built-CLI E2E for the Copilot integration passes: src/__tests__/e2e/copilot-agents.test.ts, src/__tests__/e2e/copilot-mcp.test.ts — 2/2 green.
• npm run build succeeds.
• git diff is exactly 5 files × (1 insertion / 1 deletion) on the Copilot CLI row only.

Related Issues

Closes #766

Notes for Reviewers

Docs-only, minimal diff. The three capabilities are exercised by the telemetry unit suites against realistic Copilot session-state/log fixtures and by the Copilot built-CLI E2E. A live GitHub Copilot CLI session was not run because Copilot CLI is not installed on the build host; the shipped behavior is what PR #666 implemented and tested.