benches: package as kernbench.benches, add @bench registry + list subcommand

Move benches/ -> src/kernbench/benches/ and src/kernbench/cli/probe.py ->
src/kernbench/probes/probe.py. Each bench self-registers via
@bench(name=..., description=...); kernbench list enumerates benches
with auto-assigned indices, --bench accepts kebab-case name or numeric
index. Audit at package-import time fails if any non-underscore module
forgets the decorator. ADR-0010 (EN + KO) updated to reflect the new
resolver path, list subcommand, and probes package separation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/adr/ADR-0010-api-cli-surface-and-semantics.md

@@ -7,9 +7,10 @@ Accepted
 ## Context
 
 The `kernbench` CLI is the user-facing entry point of the simulator. It
-exposes three subcommands:
+exposes four subcommands:
 
 - `run` — execute a benchmark against a topology.
+- `list` — enumerate registered benches.
 - `probe` — diagnostic utility for latency / BW measurement.
 - `web` — interactive topology viewer.
 
@@ -33,8 +34,10 @@ Required arguments:
 
 - `--topology <path>`: topology YAML file path. Loaded via
   `resolve_topology()`.
-- `--bench <name>`: benchmark name. Resolved via
-  `benches.loader.resolve_bench()`.
+- `--bench <identifier>`: benchmark identifier. Resolved via
+  `kernbench.benches.registry.resolve()`, which accepts either the
+  registered kebab-case name (e.g., `gemm-single-pe`) or a numeric
+  index from `kernbench list`.
 
 Optional arguments:
 
@@ -63,7 +66,21 @@ When `--device all` (or omitted) and the topology has multiple SIPs:
 The CLI does NOT spawn multiple OS processes or independent
 simulation runs — parallelism is internal to one simulation instance.
 
-### D4. `kernbench probe` — latency / BW diagnostic utility
+### D4. `kernbench list` — enumerate registered benches
+
+No arguments. Prints each registered bench's auto-assigned index,
+registered name, and one-line description.
+
+Benches register themselves via the `@bench(name=..., description=...)`
+decorator (`kernbench.benches.registry`). Every non-underscore module
+under `kernbench.benches/` MUST register at least one bench; a missing
+decorator raises `RuntimeError` at package import time.
+
+Indices are assigned alphabetically by name at import time. They are a
+CLI convenience (shorthand for `--bench`), not a stable API — a new
+bench inserted alphabetically will shift later indices.
+
+### D5. `kernbench probe` — latency / BW diagnostic utility
 
 Required argument:
 
@@ -87,7 +104,7 @@ that local-HBM access ≤ cross-PE-within-cube ≤ cross-cube ≤
 cross-SIP — and reports violations. Probe is a developer tool for
 verifying the latency / BW model; it is not a benchmark.
 
-### D5. `kernbench web` — topology viewer
+### D6. `kernbench web` — topology viewer
 
 Optional arguments:
 
@@ -102,7 +119,7 @@ the browser. Distinct from the static `docs/diagrams/` artifacts:
 - `kernbench web` is interactive — pan/zoom, hover for component
   attributes, switch between SIP / CUBE / PE views.
 
-### D6. Runtime API and simulation engine remain device-scoped
+### D7. Runtime API and simulation engine remain device-scoped
 
 - Runtime API calls operate on one device per invocation.
 - The simulation engine schedules all requests deterministically.
@@ -112,6 +129,10 @@ This invariant keeps each layer testable in isolation; device
 enumeration and multi-device fan-out live only in the CLI's `run`
 command (D3).
 
+The `probe` implementation lives under `kernbench.probes` (separate
+from `kernbench.benches`), reflecting that probes are diagnostic
+utilities, not registered benches.
+
 ## Consequences
 
 - Benchmark authors write single-device logic; multi-device behavior