docs(ssdl): rename SSDL shape symbols to concise form (o->, o=>)
Final vocabulary:
- ===> -> -> (codepath)
- ===>W===> -> => (wide codepath)
- o==> -> o-> (codecycle)
- oo==>oo -> o=> (wide codecycle)
- ===>B===> -> ->B-> (codepath with branch)
- ===>M===> -> ->M-> (codepath with merge)
Composites ===>B===> and ===>M===> preserved as ->B->/->M-> so the
branch/merge markers stay visible (vs. dropping them entirely).
Scope: 3 reports files (computational_shapes_ssdl_digest,
proposed_new_tracks, session_synthesis), 4 intent_dsl_survey files
(plan, report, report_v1.1, report_v1.2), 3 nagent_review files
(state.toml description, v2_2, v2_3). All old symbols verified gone
via grep; all new symbols verified present at expected locations.
ed
c4085319ff