fix(cli): prevent session flags from leaking through on retry

[kmizzi]

Summary

• Bug: happy --continue errors with "--session-id can only be used with --continue or --resume if --fork-session is also specified" while claude --continue works fine
• Root cause: Session flags (--continue, -c) were only extracted from claudeArgs when startFrom was null. On retry after error (where the SessionStart hook had already set session.sessionId), extraction was skipped — causing --continue to leak through alongside --resume <id>, producing conflicting flags
• Fix: Extract all session flags unconditionally from claudeArgs, then conditionally use the extracted values to determine startFrom. Also consume one-time flags on error in the launcher retry loop, and enhance consumeOneTimeFlags() to handle -c, -r shorthands and --session-id

Changes

claudeLocal.ts

• Move all session flag extraction (--session-id, --resume <id>, --continue) to happen unconditionally before the startFrom check
• Extracted values are only used to set startFrom when it's not already set
• Bare --resume/-r (without value) still passes through to Claude for the interactive session picker
• Fix hasContinueFlag reference → continueFlag.found

claudeLocalLauncher.ts

• Call session.consumeOneTimeFlags() in the catch block of the retry loop, preventing flags from leaking on subsequent retries

session.ts

• Enhance consumeOneTimeFlags() to handle -c (alias for --continue), -r (alias for --resume), and --session-id flag
• Simplify value detection (any non-flag next arg, not just UUID pattern)

claudeLocal.test.ts

• Add 2 regression tests for the retry scenario where sessionId is already set from a previous hook notification

Test plan

• All 12 unit tests pass (10 existing + 2 new regression tests)
• Manual test: happy --continue resumes last session without error
• Manual test: happy --resume <id> resumes specific session
• Manual test: happy -c works as alias for --continue
• Manual test: happy -r opens Claude's session picker

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