feat(cli): 0106 task 10 — aura process verb family (validate/introspect/register)

New research_docs.rs module: role-addressed process verbs with house-style
fault prose (Display-free enums phrased at the seam), the introspect
exactly-one-of usage guard (exit 2), and content-addressed registration.
Seven binary seam tests pin intrinsic-ok/refusal prose, vocabulary/block/
unwired/content-id introspection, exit codes, and the stored file's
location under the runs root.

Quality-gate finding folded in (and back into the plan): register no
longer re-derives the store path from runs_root — aura-registry now
exposes process_path/campaign_path, the same single mapping its put/get
pair routes through, so the printed path cannot drift from the store
layout.

Verification: research_docs seam tests 7/0, registry 49/0, clippy clean.

refs #189

crates/aura-cli/src/main.rs

@@ -14,6 +14,7 @@
 mod render;
 mod graph_construct;
 mod project;
+mod research_docs;
 mod scaffold;
 use render::{ChartData, ChartMeta, ChartMode, ReduceKind, Series};
 
@@ -3760,6 +3761,8 @@ enum Command {
     Reproduce(ReproduceCmd),
     /// Scaffold a new research project crate.
     New(NewCmd),
+    /// Validate, introspect, and register process documents (methodology).
+    Process(research_docs::ProcessCmd),
 }
 
 #[derive(Args)]
@@ -4708,6 +4711,7 @@ fn main() {
         Command::Runs(a) => dispatch_runs(a, &env),
         Command::Reproduce(a) => dispatch_reproduce(a, &env),
         Command::New(a) => dispatch_new(a, &env),
+        Command::Process(a) => research_docs::process_cmd(a, &env),
     }
 }