A fractional TREKRESEARCH_MAX_CONV_TURNS below 1 cleared the `n <= 0`
guard on its raw value and only then floored, so '0.5' and '0.9' became
0 and the budget became 0 x MAX_TOTAL_DIMENSIONS = 0: every turn denied,
the loop silently dead rather than bounded.
README.md:229 and docs/architecture.md:15 both promise that invalid
values fall back to 3. docs/command-modes.md:42 enumerated "empty,
non-numeric, zero, or negative" and happened to sidestep the case; the
enumeration is now exhaustive about it.
Measured before: '0.5' -> 0, '0.9' -> 0, '2.7' -> 2, '' / 'abc' / '-2'
/ '0' -> 3. Measured after: '0.5' -> 3, '0.9' -> 3, '2.7' -> 2, and
'Infinity' -> 3 (it is not a cap either).
A cap of 0 is not a narrower cap, it is an off switch. The tests pin
both directions: the fraction falls back, and allowTurn cannot report a
budget of 0 under it.
Review finding fc516799e6042e246a4b62d81903ac27c2efab84 (MINOR).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LuGhWAbWyRFBFeemfhxoVv
Kjell Tore Guttormsen
def6c05384