fix(git.md): cross-op containment rule sited inside post-resolution-summary where post-review-summary agents never read it

[dean0x]

Problem

src/assets/agents/git.md line 773 contains a sentence extending the verbatim-echo containment rule to all four comment-posting operations:

"This applies to all comment-posting operations (post-review-summary, post-resolution-summary, post-wave-report, backlink-shipped-issues)."

That sentence is inside step 5 of the ## Operation: post-resolution-summary section (which starts at line 747). A Git agent dispatched with OPERATION: post-review-summary reads only its own section (lines 360–417) and has no reason to read post-resolution-summary. Grepping the post-review-summary section for verbatim, untrusted, or external-thread returns no match in the operation's body text — the cross-op extension is invisible to the audience it names.

Partial mitigation: Principle 8 (line 972) says untrusted bodies are never echoed verbatim into devflow-authored content, so there is a global backstop. The cross-op sentence is mis-sited, not orphaned.

Evidence

• src/assets/agents/git.md:773 — cross-op sentence inside post-resolution-summary step 5 FULL-mode body
• src/assets/agents/git.md:360–417 — post-review-summary operation; no verbatim/untrusted mention in its own body
• src/assets/agents/git.md:972 — Principle 8 (global backstop)

Fix

Move the cross-op sentence into the global Principles section beside Principle 8, or replicate a one-line pointer into each of the three other named operations (post-review-summary, post-wave-report, backlink-shipped-issues). Either way, remove it from the FULL-mode body it currently lives in.

Found during review of PR #327.