feat(cli): 0106 tasks 11-12 — aura campaign verb family + workspace gates

The campaign half of research_docs.rs: validate (intrinsic always;
referential tier when a project env is discovered, with the explicit
skip line outside one), introspect (--vocabulary/--block/--unwired/
--content-id, same exactly-one-of usage guard), register via the
registry's campaign_path accessor, and RefFault prose (Display-free,
unit-pinned). Five binary seam tests (skip line, empty-axis prose +
exit 1, section vocabulary, spec-example open slots, content-addressed
registration) reuse the file's temp_cwd helper — the plan's
tempfile::tempdir() snippet deviated from the crate's zero-extra-dep
test convention and was adapted, disclosed in the loop's report.

The referential CLI branch inside a real loadable project stays
fieldtest territory by the plan's own scope note (project::load needs a
built dylib); its logic is pinned by the aura-registry tests.

Gates: cargo test --workspace 916/0 (885 pre-cycle + 31 new), clippy -D
warnings clean, cargo doc --no-deps 0 warnings. The worked spec example
runs end-to-end headless: author both documents as text, validate with
per-tier report lines, introspect vocabularies and open slots, obtain
stable content ids, register into the store — no Rust compile, no run
executed.

closes #189

crates/aura-cli/src/main.rs

@@ -3763,6 +3763,8 @@ enum Command {
     New(NewCmd),
     /// Validate, introspect, and register process documents (methodology).
     Process(research_docs::ProcessCmd),
+    /// Validate, introspect, and register campaign documents (experiment intent).
+    Campaign(research_docs::CampaignCmd),
 }
 
 #[derive(Args)]
@@ -4712,6 +4714,7 @@ fn main() {
         Command::Reproduce(a) => dispatch_reproduce(a, &env),
         Command::New(a) => dispatch_new(a, &env),
         Command::Process(a) => research_docs::process_cmd(a, &env),
+        Command::Campaign(a) => research_docs::campaign_cmd(a, &env),
     }
 }