feat(cli): plane-grouped --help + clap 4.6.1 (RFC-010 Slice 2) (#220)

* chore(deps): bump clap to 4.6.1

Workspace constraint "4" → "4.6" so the resolver picks up the 4.6 line
(a plain `cargo update` stayed on 4.5.x). clap 4.5.58 → 4.6.1
(clap_builder 4.6.0, clap_derive 4.6.1). Minor bump, no API breakage; the
workspace builds and all CLI suites pass unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* feat(cli): group --help by plane (RFC-010 Slice 2)

Slice 1 declared the planes (the command_plane table + the wrong-plane
guard); this makes them visible in `--help`. clap can't print labeled
heading rows between subcommand groups (verified against the source —
help_heading is args-only, {subcommands} is one flat block), so per the
chosen approach: cluster + legend.

- Reorder the `Command` enum into plane bands (clap lists subcommands in
  declaration order): data (query, mutate, load, branch, snapshot, export,
  commit, schema, graphs) → storage/local-graph ops (init, optimize,
  repair, cleanup, lint, queries) → control (cluster) → session (policy,
  embed, login, logout, config, version). No magic display_order numbers —
  the source order IS the help order, with band comments for readers. The
  band placement matches `command_plane` (lint/queries are storage-plane:
  they reject --server), so the help grouping and the guard agree.
- Add an `after_help` legend on `Cli` naming the planes. Written to
  describe the planes (not enumerate every command) so it doesn't drift.

Help-polish (post-review): hide the deprecated `ingest` from the list
(still a valid command); trim the long `login` and `--as` descriptions to
one line each so the columns don't blow up.

The behavioral source of truth for planes stays `planes::command_plane`;
this ordering is its cosmetic counterpart.

Test: `help_groups_commands_by_plane` pins the legend phrase + the cluster
ordering (query < optimize < cluster). Doc: a line under cli-reference's
*Command planes* section.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* feat(cli): qualify mixed-plane commands in the --help legend

Addresses the Greptile P2 on #220: the legend placed `schema` entirely in
Data and `queries` entirely in Storage, but per `command_plane` the
subcommands differ — `schema plan` is storage-plane (rejects --server) and
`queries list` is session (no graph). A user reading the legend then running
`schema plan --server` would hit a rejection contradicting it. The Commands
list is one entry per top-level command (necessarily coarse), so the legend
carries the nuance: `schema [plan: storage]` and `queries [list: session]`.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Cargo.lock

@@ -83,9 +83,9 @@ dependencies = [
 
 [[package]]
 name = "anstream"
-version = "0.6.21"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
+checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
 dependencies = [
  "anstyle",
  "anstyle-parse",
@@ -104,9 +104,9 @@ checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
 
 [[package]]
 name = "anstyle-parse"
-version = "0.2.7"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
 dependencies = [
  "utf8parse",
 ]
@@ -1314,9 +1314,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.5.58"
+version = "4.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "63be97961acde393029492ce0be7a1af7e323e6bae9511ebfac33751be5e6806"
+checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -1324,9 +1324,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.58"
+version = "4.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f13174bda5dfd69d7e947827e5af4b0f2f94a4a3ee92912fba07a66150f21e2"
+checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
 dependencies = [
  "anstream",
  "anstyle",
@@ -1336,9 +1336,9 @@ dependencies = [
 
 [[package]]
 name = "clap_derive"
-version = "4.5.55"
+version = "4.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a92793da1a46a5f2a02a6f4c46c6496b28c43638adea8306fcb0caa1634f24e5"
+checksum = "f2ce8604710f6733aa641a2b3731eaa1e8b3d9973d5e3565da11800813f997a9"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -5323,9 +5323,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.44"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "21b2ebcf727b7760c461f091f9f0f539b77b8e87f2fd88131e7f1b433b3cece4"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
 dependencies = [
  "proc-macro2",
 ]