Merge origin/master: adopt the DeepSeek Harness SDK product name

Reconciliations beyond textual conflicts:
- product rename (DeepSeek Code -> DeepSeek Harness SDK) applied to the
  PR-added assertion in system-prompt.spec.ts that master's rename
  commit could not reach
- architecture.md: master's rewrite kept; this PR's prompt-assembly
  semantics re-added in the new doc's voice (Turn Flow footnote +
  service-spine row), within the 1630-word ceiling
- cordis catalog regenerated into master's split events.md/services.md
  (events-and-services.md deleted); module graph and doc graphs
  regenerated to pick up this PR's new events and dependency edges

docs/rfc/README.md

@@ -170,6 +170,7 @@ Do NOT write one for a mechanical or local choice (a variable name, a one-file r
 | [Classify RFCs by kind via path-encoded subdirectories](implemented/process/2026-06-20-rfc-classification.md) | 2026-06-20 |
 | [Bilingual documentation via paired sibling files and a pairing gate](implemented/process/2026-07-02-bilingual-docs-and-pairing-gate.md) | 2026-07-02 |
 | [Generated tool-schema catalog (boot-and-harvest)](implemented/process/2026-07-02-tool-schema-catalog.md) | 2026-07-02 |
+| [Documentation graph index for maintainers and SDK users](implemented/process/2026-07-03-documentation-graph-atlas.md) | 2026-07-03 |
 | [JSDoc completeness gate for the cordis surface](implemented/process/2026-07-04-cordis-jsdoc-completeness-gate.md) | 2026-07-04 |
 | [Documentation tiers, budgets, and the ceiling gate](implemented/process/2026-07-04-doc-tiers-and-budgets.md) | 2026-07-04 |
 | [Generate the RFC index tables](implemented/process/2026-07-04-generate-rfc-index-tables.md) | 2026-07-04 |