feat: add success criteria, constraints, and mode to the goal schema

Goals can now carry successCriteria (--success), constraints/non-goals
(--constraints/--non-goals), and a mode of normal or ordered (--mode,
sisyphus alias). parseGoalArguments gains string/enum flag support and a
meta object; fields thread through state, persistence, the injected goal
block (escaped, new success_criteria/constraints structural tags),
creation output, and /goal status. Ordered mode adds a strict-sequence
instruction. Adds normalizeMode plus unit/parsing/command tests.
Items 4.1, 4.2, 4.3.