fix 11201: fix auto-title guard to use >= 2

[vominh1919]

Fixes #11201

maybe_auto_title() claimed to generate titles only after the first exchange, but the guard was > 2 instead of >= 2, allowing auto-titling on the second exchange.

[alt-glitch]

Duplicate of #11313 — both fix the same off-by-one in maybe_auto_title() for #11201.

[alt-glitch]

Duplicate of #11313

[teknium1]

Thanks for isolating the boundary condition.

Problems

• Current main intentionally permits title generation during the first 1–2 exchanges: agent/title_generator.py:185-190 says “Be generous: generate on first 2 exchanges,” and the original feature commit e5fc916814e6937b2a9d4fa6baa8d3e42b6f79fb records that behavior explicitly. Changing the guard to >= 2 removes that fallback rather than fixing an accidental off-by-one.
• The PR adds no boundary regression test; current coverage at tests/agent/test_title_generator.py:263-280 asserts skipping only after three user messages.

Suggested changes

• Retain the current guard unless maintainers explicitly choose a first-exchange-only policy. If that policy changes, update the intent comment and add coverage for exactly two user messages; duplicate PR fix(agent): restrict auto-title to first exchange only #11313 includes that test direction.

Automated hermes-sweeper review.