import: remediate review findings — ledger gate, docs, message split

Delegates the refuse-gate to ledgerDegraded(), lifts its console message into a
pure testable fold, fixes stale doc line citations and an inaccurate outcome-enum
comment, and splits the rename counter into collision-vs-sanitize.

docs/PLAN.md

@@ -2366,7 +2366,7 @@ These bind every track in this phase, in addition to the plan-wide set above.
   touching it must **cite, not restate**.
 - **Export is read-only against the project.** No ext-state write, no `bumpBankGeneration()`,
   no undo point. Import does the opposite: it bumps the generation
-  (`src/shell/persist/session.h:108`) so live ReaSampler 9000 instances reload, and batches
+  (`src/shell/persist/session.h:114`) so live ReaSampler 9000 instances reload, and batches
   its index mutation into one Ctrl-Z through `persistBankOp`.
 - **All-or-nothing on both sides.** No partial export, no partial import. A truncated
   `.rsbank` must never exist on disk (temp file + atomic rename, the Ψ-W2-T2 precedent); a
@@ -2396,10 +2396,13 @@ new directories** (`src/core/package/`, `src/shell/package/`) that no other phas
 not read here. The only pre-existing files any Ε track edits are named per track below —
 `core/tracking/origin_ledger` (W1-T3, exclusively), the root `CMakeLists.txt`
 `add_subdirectory` list (W1-T1 and W1-T2, one line each), `src/app/main.cpp` and the panel's
-bank menu (W2-T1 and W2-T2, one registration line and one menu row each), and
+bank menu (W2-T1 and W2-T2, one registration line and one menu row each),
 `core/model/bank_book.{h,cpp}` (W2-T2 only — **one additive public `const` member**, required
-by the Ε-F2 auto-suffix rule so the name fold keeps its single home). **No Ε track
-touches `core/instrument/`, `shell/instrument/`, or any capture backend.**
+by the Ε-F2 auto-suffix rule so the name fold keeps its single home), and
+`shell/persist/session.h` (W2-T2 only — one additive public accessor, `ledgerStatus()`, so the
+import gate can key on `LedgerStatus` alone without going through `pruneDryRun()`'s
+enumeration+scan). **No Ε track touches `core/instrument/`, `shell/instrument/`, or any
+capture backend.**
 
 ---
 
@@ -2764,7 +2767,7 @@ fold, it does not add a second one), `origin_ledger` (Ε-W1-T3's).
   `"Drums 3"` — a bare trailing integer is indistinguishable from `"Kit 808"`); the probe
   **fills gaps** (first-free, not highest-plus-one, so it is a pure function of the current
   name set); the probe **terminates** by pigeonhole within `B + 1` candidates for `B` banks,
-  so **no arbitrary cap**; and the fold is `BankBook`'s own (`bank_book.h:252-258`), reached
+  so **no arbitrary cap**; and the fold is `BankBook`'s own (`bank_book.h:263-269`), reached
   through the new public member, never re-implemented in `import_plan`. Sample display names
   are **not** suffixed, and `slot_map` positions are untouched.
 - **Always a new bank; never a merge (Ε-F2, ruled).** The import creates a bank — it never
@@ -2787,7 +2790,7 @@ fold, it does not add a second one), `origin_ledger` (Ε-W1-T3's).
   remain as orphans until a prune reclaims them — the same designed window a non-empty bank
   delete already produces (`core/model/CLAUDE.md`'s sample-removal section). The user-facing
   summary says so.
-- **`bumpBankGeneration()` on success** (`session.h:108`), so live instances reload.
+- **`bumpBankGeneration()` on success** (`session.h:114`), so live instances reload.
 - **No timeline item is placed. Ever.**
 - **A new FOREVER-STABLE command id**, minted the same way T1's is.