feat: prompt to clear contexts when switching profiles

[aru-amedeo]

Summary

• acloud config profile use <name> now asks whether to clear all contexts after switching profiles, since project IDs are tenant-scoped and unlikely to be valid across profiles
• Interactive mode: prompts Contexts may not be valid for the new profile. Clear all contexts? (y/N):
• Non-interactive mode (piped stdin / scripts): silently keeps contexts — no change to existing behaviour
• New --clear-contexts flag: clears without prompting, useful in CI or automation

Changes

File	Change
cmd/prompt.go	Added promptConfirmOptional — yes/no prompt that returns false silently in non-interactive mode
cmd/context.go	Added ClearAllContexts() — resets context file to empty state
cmd/config.go	ConfigProfileUseRun wires the prompt + flag; --clear-contexts registered in init()
cmd/config_profile_test.go	Two new tests: flag forces clear; non-interactive preserves contexts
docs/website/docs/configuration.md	Callout documenting the behaviour and the flag

Test plan

• acloud config profile use staging in a terminal — prompt appears, y/N works
• acloud config profile use staging --clear-contexts — clears without prompt
• Pipe to stdin (echo "" | acloud config profile use staging) — no prompt, contexts unchanged
• Unit tests: go test ./cmd/ -run TestConfigProfileUse — 4 pass
• Full suite: ACLOUD_TEST_SKIP_CLIENT=true go test ./cmd/ — no regressions

Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.09%. Comparing base (a3bc509) to head (0ce82f0).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/config.go	81.81%	1 Missing and 1 partial ⚠️
cmd/prompt.go	75.00%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #236   +/-   ##
=======================================
  Coverage   78.09%   78.09%           
=======================================
  Files          53       53           
  Lines       12438    12461   +23     
=======================================
+ Hits         9713     9732   +19     
- Misses       1565     1567    +2     
- Partials     1160     1162    +2     

Flag	Coverage Δ
unittests	78.09% <83.33%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.