Copilot Fix(CI Failure): Bump pinned copilot-version default to 1.0.82

[github-actions]

Summary of issue

The scheduled version-pin-drift job in .github/workflows/test-copilot.yml failed on run 33367494749 because the copilot-version default pinned in action.yml (1.0.80) has fallen behind the @github/copilot npm packages @latest version (1.0.82).

Somewhere, a version bump elf forgot to update our pin and now the CI robot is throwing a well-deserved tantrum on a schedule. 🤖⏰

https://github.com/austenstone/copilot-cli/actions/runs/33367494749/job/91095958541#step:3:1

💥 Error Log

##[warning]copilot-version default is pinned to 1.0.80 but @latest is 1.0.82
##[error]Process completed with exit code 1.

🕵️‍♂️ Diagnosis

The version-pin-drift job compares the copilot-version input default in action.yml against the latest published version of @github/copilot on npm. This check is designed to intentionally fail (test "${{ github.event_name }}" != "schedule") on scheduled runs when a drift is detected, so maintainers get notified that the pinned default is stale. This is not a code regression — it is the check working as intended, flagging that action.yml needs a version bump.

🛠️ Proposed Fix

Bump the pinned copilot-version default from 1.0.80 to 1.0.82 in action.yml, and update the matching example/default references in README.md to keep docs in sync.

Validation performed:

• Confirmed via npm view @github/copilot@latest version that latest is 1.0.82.
• Parsed action.yml with python3 -c "import yaml; ..." to confirm the new default reads back as 1.0.82.
• Validated .github/workflows/test-copilot.yml still parses as valid YAML.

[github-actions]

Note: the PR-triggered "Test Copilot CLI" run shows action_required — this is the repo's workflow-approval gate for actions touching action.yml, not a failure of this fix. The version-pin-drift fix itself was validated locally: python3 -c "import yaml; ..." confirms action.yml now resolves copilot-version default to 1.0.82, matching npm view @github/copilot@latest version.