feat(config): modes - a mode is an artifact kind, the lenses it runs and its effort

The config defines the modes (modes.<name>): the kind of artifact the mode
reviews - reply, series or commits, the three shipped partitions; a kind
is a mode of its own name - the lenses it runs, in its kind's gate order,
and the effort it runs at, else the kind's default (max for a reply or a
series, xhigh for a commit range). `run --mode` names any of them, the
dump records mode and kind, and everything that decided by the mode's
name - the partition and hash, the prompts, the schemas, the disposition
and reuse-key rules, what the CLI requires - decides by the kind.

Every lens stays off until a mode lists it; lenses.<name>.run is retired
with a warning that says so, and a lens of another kind, a name that is
no lens, a lens listed twice and an unknown effort are config problems.
The defaults run no lens; the template ships the three kinds as modes
with every lens of their kind at the kind's effort, to trim (the owner's
ruling of 2026-11-01), and init says so as it writes it - a kept config
is the repository's own, and only one that lists no lens gets a step.

The readers of the retired key follow: the CI smoke config, the shipped
skill, the procedure (its description of the config as well as its
mechanics), the manifest template, the run's messages and the comments
that named the three modes. The run lock, the run numbers and the dump
names are the kind's, so one full run per hash holds across the modes
of a kind and their rounds count on together; the dump says which mode
ran. The database broker starts for a lens the mode runs, as every other
reader of the lenses off reads them. A named mode runs through the CLI
in the kernel-modes test.

interfaces/Crafter.Review-Config.cppm

@@ -40,8 +40,7 @@ export namespace Crafter::Review::Config {
     // repository's git identity.
     std::vector<std::string> Authors(const Json& config, const std::filesystem::path& repo);
     std::string GitUserEmail(const std::filesystem::path& repo);
-    // The lens files the config turns off (lenses.<name>.run = false), in gate
-    // order.
+    // The lens files no mode lists (what runs nowhere: the slots and init).
     std::vector<std::string> LensesOff(const Json& config);
     // {lens file: environment} for every lens of the table, as the config
     // holds it (validated elsewhere).
@@ -66,6 +65,23 @@ export namespace Crafter::Review::Config {
     // What is wrong with those files: one missing, or one
     // Prompt::ReadSection cannot use.
     std::vector<std::string> SectionProblems(const Json& config, const std::filesystem::path& repo);
+    // A mode as the config defines it (modes.<name>, 2026-11-01): the
+    // artifact kind it reviews, the lens files it runs in the table's order,
+    // and the effort it runs at when set. nullopt: no such mode, or one
+    // whose kind or lens list cannot be read; lenient on the rest Validate
+    // refuses (a lens of another kind dropped, an unknown effort kept),
+    // which no command reaches: each stops on the config's problems first.
+    struct Mode {
+        std::string name;
+        std::string kind;
+        std::vector<std::string> lensFiles;
+        std::optional<std::string> effort;
+    };
+    std::optional<Mode> ModeOf(const Json& config, std::string_view name);
+    // The configured mode names, in the config's order.
+    std::vector<std::string> ModeNames(const Json& config);
+    // The lens files of the mode's kind that the mode does not list.
+    std::vector<std::string> LensesOff(const Json& config, std::string_view mode);
     // The example a consumer starts from (process/templates/config.json is
     // this, rendered).
     Json Example();