hive-c0re: render the new agent option paths into generated agent flakes

meta.rs writes each agent's flake, and it still named the pre-move
`hyperhive.*` paths — so every agent rebuild would print a rename
deprecation warning about a line no human wrote and no operator could fix.
A warning nobody can act on trains everyone to ignore the ones that matter,
which is the whole value of the alias shims.

Repoints the FORWARDED_VAR_OPTIONS table and every other emitted option
assignment (otel.*, docs.source, claudeCodePath, github.enable, user.name,
claudeMemoryMaxBytes) to `services.hyperhive.agent.*`, with the test
expectations that pin the rendered text. The flake input named `hyperhive`
(`hyperhive.url`, `hyperhive.inputs.nixpkgs.follows`,
`hyperhive.nixosConfigurations.*`), hive-tier `services.hyperhive.*` paths,
and the `@hyperhive.local` git identity share the word and are untouched.

Also repoints the same option paths where they appear in comments, rustdoc
and runtime message strings across the other crates — a refusal message
naming `hyperhive.allowedRecipients` sends an operator to a path that will
stop existing. Prose under docs/ is deliberately not in this commit.

Refs #4473

hive-agent/src/prompt.rs

@@ -40,7 +40,7 @@ pub fn render(
         .replace("{operator_pronouns}", operator_pronouns)
         .replace("{hive_identity}", &hive_identity)
         .replace("{swarm_identity}", &swarm_identity);
-    // When the reference docs are mounted in-container (`hyperhive.docs.enable`
+    // When the reference docs are mounted in-container (`services.hyperhive.agent.docs.enable`
     // wires `HIVE_DOCS_DIR` + `claude --add-dir`), append a single pointer
     // sentence so the agent knows they exist. Additive: it doesn't replace the
     // agent's own memory/project instructions. Absent env → no change.
@@ -129,7 +129,7 @@ pub async fn write_system_prompt(_socket: &Path, label: &str) -> Result<PathBuf>
     // verbatim (single-hive deployments see no diff).
     let hive_name = crate::identity::hive_name();
     let swarm_name = crate::identity::swarm_name();
-    // `hyperhive.docs.enable` sets HIVE_DOCS_DIR (and the harness passes it to
+    // `services.hyperhive.agent.docs.enable` sets HIVE_DOCS_DIR (and the harness passes it to
     // claude via `--add-dir`); when present, render() appends a pointer line.
     let docs_dir = std::env::var("HIVE_DOCS_DIR")
         .ok()