fix(phase3): enable polling when decisions stream from Phase 2

[twaugh]

Phase 3 wasn't updating the UI for blocks 2+ when decisions were streaming in from Phase 2's background worker. The polling timer never started because initialization logic incorrectly marked all blocks as "ready" when it detected a non-empty decisions list.

Root Cause:
The initialization code (lines 167-174) assumed only two scenarios:

1. Empty decisions → streaming will start, don't mark blocks ready
2. Non-empty decisions → complete pre-generated list (tests), mark ALL ready

But there was a third scenario it didn't handle:
3. Partially populated decisions → streaming from Phase 2, only mark blocks WITH decisions as ready

This caused on_mount() to calculate all_complete=True (5 ready / 5 total), preventing the polling timer from starting.

Fix:

1. Use auto_start_workers flag to distinguish test mode (True) from production mode with shared streaming list (False)
2. In production mode, only mark blocks with decisions as ready
3. Change task check from isinstance() to hasattr() to support test MockApp

Result:

• Polling starts correctly when blocks_ready < total_blocks
• UI updates as new decisions stream in from Phase 2
• All 56 Phase 3 tests pass

Assisted-by: Claude Code

[codecov-commenter]

Codecov Report

❌ Patch coverage is 40.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 84.75%. Comparing base (a727fb3) to head (4dc0c01).

Files with missing lines	Patch %	Lines
src/logsqueak/tui/screens/integration_review.py	40.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #34      +/-   ##
==========================================
+ Coverage   84.57%   84.75%   +0.18%     
==========================================
  Files          48       48              
  Lines        5083     5084       +1     
==========================================
+ Hits         4299     4309      +10     
+ Misses        784      775       -9     

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