Sync pact-protocols.md with v3.5.0 and tighten imPACT/wrap-up additions

[michael-wojcik]

Problem

After merging PR #187 (SDK optimization, v3.5.0), two things need follow-up:

1. pact-protocols.md is out of sync

pact-protocols.md duplicates content from standalone protocol files but wasn't updated in PR #187. Three sections are stale:

• imPACT section: Still says "Two questions, Three outcomes" — should be "Three questions, Five outcomes" (Resume + Terminate added)
• Algedonic section: Missing broadcast HALT for parallel agents
• Stall Detection section: Doesn't reference the TeammateIdle hook

2. imPACT.md and wrap-up.md additions are verbose

PR #187 added content that could be more concise:

• imPACT.md: The "When to terminate" block (~12 lines) can be condensed — criteria can be a single sentence, TaskStop note shortened to one line, redundant "After termination" paragraph removed
• wrap-up.md: The > Note: about session_end.py belt-and-suspenders is unnecessary in a command doc — remove it, keep the 3 cleanup steps