spec(SHARD-WP-0002): re-fold synthesis v3 + computational page model (T17, T18)

Folds the later syntheses into the federation/adapter-contract workplan:
- T11 capability spectra 13 -> 15 (+provenance granularity, +computational/
  liveness); +derive-projection/execute verbs
- T12 four computational page shapes (UC-83/84) + typed-graph statements
- T13 paired-text/nbdime + DB-version-rows + partial-history honesty
- T14 git-IS-store + direct-DB + image-is-not-a-store boundary
- T15 structured-re-evaluable-value opacity point; non-Markdown computed
- T16 two-axis projection model + moldable view registry + named-chunk transclusion
- NEW T17 federation-model taxonomy (fork+journal / VCS-replication+ping /
  query-join / feed / activity-streams / engine-mirror; selectable+composable)
- NEW T18 computational/executable content (in scope as page-model+projection,
  out as execution platform; execute = gated capability)
- Context/decision-tables/acceptance/order updated; UC range -> UC-26-UC-84

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.claude/ralph-loop.local.md

@@ -1,21 +0,0 @@
----
-active: true
-iteration: 1
-session_id: b24b53ca-a25b-4a18-8331-925c4100d39f
-max_iterations: 20
-completion_promise: "HEUREKA"
-workplan_id: SHARD-WP-0004
-workplan_file: workplans/SHARD-WP-0004-computational-knowledge-systems.md
-started_at: "2026-06-14T20:35:07Z"
----
-
-Read the workplan at `workplans/SHARD-WP-0004-computational-knowledge-systems.md`.
-
-If every task has `status: done` AND frontmatter `status: done`:
-run `rm -f .claude/ralph-loop.local.md` first (deactivates the loop so the stop hook exits cleanly),
-then output <promise>HEUREKA</promise>.
-
-Otherwise implement the next `todo` task as described in the workplan.
-Set task `in_progress` when starting, `done` when complete.
-When all tasks are done set frontmatter `status: done`.
-