adding tests, small improvement / better guard

[Soph]

This is on top of #556

• adding a better guard to make sure the session really ended
• added FullyCondensed skip to filterSessionsWithNewContent - this prevents unnecessary sessionHasNewContent calls during PrepareCommitMsg, which is on the git commit hot path
• adding unit tests
• adding an integration test validating we can get reactive those sessions

[cursor]

PR Summary

Low Risk
Small guard changes in git hook session filtering/skip logic plus expanded test coverage; behavior changes are narrowly scoped and validated by new unit/integration tests.

Overview
Ensures FullyCondensed is treated as an ENDED-only optimization: PostCommit/PrepareCommitMsg now skip sessions only when state.FullyCondensed && state.Phase==ENDED, avoiding accidental skipping of non-ended sessions.

Adds coverage to lock in the intended lifecycle: unit tests assert ActionClearEndedAt clears FullyCondensed, PostCommit tests validate when the flag is set and that fully-condensed ENDED sessions are skipped on later commits, and a new integration test verifies reactivating an ENDED+fully-condensed session clears the flag so future commits aren’t silently ignored.

^{Written by Cursor Bugbot for commit 70cc27d. Configure here.}

[Copilot]

Pull request overview

This PR adds defensive improvements and comprehensive test coverage on top of PR #556, which introduced the FullyCondensed flag for performance optimization. The PR strengthens the guard conditions for the FullyCondensed flag, adds the optimization to the PrepareCommitMsg hot path, and provides thorough unit and integration tests for the full lifecycle.

Changes:

• Added && state.Phase == session.PhaseEnded guard to both PostCommit and filterSessionsWithNewContent skip conditions, making the FullyCondensed invariant explicit and defensive
• Added three new unit tests covering: setting FullyCondensed after ENDED session condensation, skipping on subsequent commits, and verifying non-ENDED sessions never get the flag
• Added an integration test verifying that reactivating a fully-condensed ENDED session correctly clears the flag (the critical safety scenario)

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
cmd/entire/cli/strategy/manual_commit_hooks.go	Added && state.Phase == session.PhaseEnded guard to the FullyCondensed skip conditions in both PostCommit loop and filterSessionsWithNewContent
cmd/entire/cli/session/phase_test.go	Expanded TestApplyTransition_ClearsEndedAt to a table-driven test covering both FullyCondensed=true and FullyCondensed=false cases, verifying the flag is cleared on reactivation
cmd/entire/cli/strategy/phase_postcommit_test.go	Three new unit tests for the FullyCondensed flag lifecycle in PostCommit
cmd/entire/cli/integration_test/fully_condensed_test.go	New integration test for the complete reactivation-clears-flag scenario