fix(taskctl): Composer creates overly sequential task chains — should only add depends_on for real data dependencies

[randomm]

Composer prompt rule 4 says tasks that others depend on should have lower priority numbers, but the Composer interprets this as always chaining tasks sequentially. For issue #262 it created a 4-task chain where each depends on the previous, when tasks 1+3+4 could run in parallel. The Composer prompt should emphasize: only add depends_on when a task truly REQUIRES the output of a previous task (e.g. calling a function defined in task A). Logical ordering preference is NOT a dependency.