docs: move internal design docs into docs/rfcs/

docs/CONFIGURATION.md

@@ -405,7 +405,7 @@ Unknown posture names or unknown keys inside a harness profile fail config
 deserialization instead of silently becoming `custom`. That is intentional:
 once runtime wiring consumes these profiles, a typo should be visible.
 The v0.9 implementation order and automatic-creator boundary are documented in
-[`HARNESS_PROFILE_CUTLINE.md`](HARNESS_PROFILE_CUTLINE.md).
+[`HARNESS_PROFILE_CUTLINE.md`](rfcs/HARNESS_PROFILE_CUTLINE.md).
 
 ## Environment Variables
 

docs/V0_9_0_RELEASE_ACCEPTANCE.md

@@ -63,8 +63,8 @@ config source, result, and follow-up issue or PR.
 | Live `workflow_run`, worktree application, provider calls, and TraceStore writes are deferred until cancellation/replay/atomicity semantics pass | WhaleFlow steward | defer | #2669 and #2679 remain open for live runtime execution, provider calls, TraceStore writes, Arcee/student replay, and CLI/TUI workflow mode; current v0.9 branch ships mock executor/replay foundations only. |
 | Model Lab / Hugging Face MVP is included or deferred with release-note wording | model-lab steward | ship provider/MCP docs foundation / defer native Model Lab MVP | v0.9 ships the Hugging Face chat-provider route, provider docs, and `/hf` concept/MCP status helpers only. Native Hub search, model passports, Spaces/Jobs workflows, and Model Lab eval/export surfaces remain deferred to #2705/#2707/#2710/#2712/#2727. |
 | HarnessProfile runtime MVP is deferred; schema/resolver foundation ships with release-note wording | harness steward | ship foundation / defer runtime | #2844 (`efbcc681a`) documents the cutline; `HarnessPosture` / `HarnessProfile` config schema and strict validation are present; a pure resolver matches provider/model routes without changing runtime behavior; seed-profile runtime selection, telemetry, and status display remain follow-up work. |
-| `codebase_search` MVP is included or deferred with release-note wording | search steward | defer runtime / ship design doc | `docs/CODEBASE_SEARCH_DESIGN.md` is explicitly doc-only and says no catalog code ships in this cycle; runtime tool registration, index/eval fixtures, and search implementation remain deferred to #2680. |
-| External memory remains explicit/optional per `WHALEFLOW_EXTERNAL_MEMORY.md` | memory steward | ship | #2842 (`a7052751e`) added the external-memory cutline: optional/explicit workflow node/plugin only, visible state/owner/storage/scope, and no hidden default context substrate. |
+| `codebase_search` MVP is included or deferred with release-note wording | search steward | defer runtime / ship design doc | `docs/rfcs/CODEBASE_SEARCH_DESIGN.md` is explicitly doc-only and says no catalog code ships in this cycle; runtime tool registration, index/eval fixtures, and search implementation remain deferred to #2680. |
+| External memory remains explicit/optional per `rfcs/WHALEFLOW_EXTERNAL_MEMORY.md` | memory steward | ship | #2842 (`a7052751e`) added the external-memory cutline: optional/explicit workflow node/plugin only, visible state/owner/storage/scope, and no hidden default context substrate. |
 
 ## Remote Workbench
 

docs/VISION_NORTH_STAR.md

@@ -143,7 +143,7 @@ reuses the existing `ignore`/`WalkBuilder` path.
 
 **Dependencies.** rusqlite/FTS5; the Intent Router (§1) for the
 `codebase_search` verb; the trace store (§6/§8) for history retrieval. **Full
-design lives in `docs/CODEBASE_SEARCH_DESIGN.md`** (to be written this cycle).
+design lives in `docs/rfcs/CODEBASE_SEARCH_DESIGN.md`** (to be written this cycle).
 
 ---
 
@@ -281,7 +281,7 @@ clearable, and scoped**:
 6. **Cached-main overlay** — promoted lessons from the cached main branch
    (`/overlay`, §9).
 7. **External memory (Aleph)** — large local data via the `aleph` skill;
-   see `docs/WHALEFLOW_EXTERNAL_MEMORY.md` for the v0.9.0 cutline that keeps
+   see `docs/rfcs/WHALEFLOW_EXTERNAL_MEMORY.md` for the v0.9.0 cutline that keeps
    this optional, explicit, inspectable, and out of the default path.
 
 **Why it helps weaker models.** The model never has to *guess* where a fact
@@ -458,7 +458,7 @@ cycle):
   active + actionable RLM/field errors). Subagent legacy-name cleanup +
   guardrail tests rebased on #2684.
 - **Docs:** this north star, plus `docs/TOOL_LIFECYCLE.md`,
-  `docs/CODEBASE_SEARCH_DESIGN.md`, `docs/SKILL_INVOCATION_DESIGN.md`.
+  `docs/rfcs/CODEBASE_SEARCH_DESIGN.md`, `docs/SKILL_INVOCATION_DESIGN.md`.
 - **No tool-catalog code:** the diet (§3), the Intent Router (§1), and the
   hybrid index (§2) are **documented, not coded** this cycle.