docs: 1.0 documentation restructure

Split root CLAUDE.md into 19 per-directory files scoped to their source area.
Roll v0 history into docs/ARCHIVE.md; retire CONTEXT.md, CONTEXT-ARCHIVE.md,
PLAN.md, COMPLETED.md. Move plan docs under docs/. Rescue 9 live deferrals
into docs/TODO.md.

docs/product/design-view.md

@@ -1,8 +1,9 @@
 # Design View — product notes
 
 Framing, rationale, and design-direction calls behind the **Design View** phase.
-The tickable spec lives in `PLAN.md` (Phase D) and the authoritative technical
-detail in `CONTEXT.md` (§Design View). This doc holds the *why* — the workflow
+The tickable spec's landed history lives in `docs/ARCHIVE.md` (Phase D) and the
+architecture detail in `src/core/view/CLAUDE.md` + `src/shell/view/CLAUDE.md`
+(§Design View). This doc holds the *why* — the workflow
 narrative, the N-mode reasoning, the screenset differentiation, and the
 design-direction recommendations — so those don't clutter the build docs.
 
@@ -339,8 +340,7 @@ tooltip on the switch.
    `docs/design/`), say so and it moves. Flagging because establishing the
    directory is a project convention, not mine to assume silently.
 2. **Phase namespace.** Proposed **Phase D** (a lettered namespace) rather than
-   M12 — see PLAN.md rationale. Confirm you're happy with letters for parallel,
-   non-capture phases.
+   M12. Confirm you're happy with letters for parallel, non-capture phases.
 3. **SDK name correction.** The brief cited `B_SHOWINMCP`; the verified SDK flag
    for mixer-panel visibility is **`B_SHOWINMIXER`** (SDK header line 2235). The
    spec uses the verified name. Just flagging the discrepancy so it isn't a