fix: register outside a project refuses instead of creating a stray store (closes #305)

register_process and register_campaign now carry the same
env.provenance() no-project guard as their show/runs siblings, refusing
with exit 1 and the missing-Aura.toml prose instead of letting
Env::runs_root()'s relative fallback materialise ./runs/ in an innocent
cwd. Five pre-existing register tests ran from a bare temp cwd and were
reaching their asserted behaviour only through this bug; they now run
inside the fresh_project() fixture, preserving their original property
(content addressing, intrinsic-validation refusals) in a real project.

Verified: the RED E2E test (register_outside_a_project_refuses_and_
leaves_no_store, both verbs, refusal + no side-effect store) observed
GREEN by the loop's independent verify alongside the full suite.

crates/aura-cli/src/research_docs.rs

@@ -250,6 +250,15 @@ fn validate_process_file(file: &PathBuf) -> Result<(), String> {
 }
 
 fn register_process(file: &PathBuf, env: &Env) -> Result<(), String> {
+    if env.provenance().is_none() {
+        let cwd = std::env::current_dir()
+            .map(|d| d.display().to_string())
+            .unwrap_or_default();
+        return Err(format!(
+            "process register needs a project: the document store lives under the \
+             project store root (no Aura.toml found up from {cwd})"
+        ));
+    }
     let doc = parse_valid_process(file)
         .map_err(|m| format!("refusing to register: {m}"))?;
     let canonical = process_to_json(&doc);
@@ -580,6 +589,15 @@ fn validate_campaign_file(file: &PathBuf, env: &Env) -> Result<(), String> {
 }
 
 fn register_campaign(file: &PathBuf, env: &Env) -> Result<(), String> {
+    if env.provenance().is_none() {
+        let cwd = std::env::current_dir()
+            .map(|d| d.display().to_string())
+            .unwrap_or_default();
+        return Err(format!(
+            "campaign register needs a project: the document store lives under the \
+             project store root (no Aura.toml found up from {cwd})"
+        ));
+    }
     let doc = parse_valid_campaign(file)
         .map_err(|m| format!("refusing to register: {m}"))?;
     let canonical = campaign_to_json(&doc);