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-priv-sock/src/lib.rs

@@ -510,7 +510,7 @@ pub enum PrivRequest {
     /// Write `github-token` into `AGENT_STATE_ROOT/<agent_name>/state/github-token`.
     ///
     /// The operator-supplied GitHub personal access token (PAT) for the
-    /// agent's GitHub integration (`hyperhive.github.enable`). Same write
+    /// agent's GitHub integration (`services.hyperhive.agent.github.enable`). Same write
     /// semantics as
     /// `WriteAgentForgeToken` — validates `agent_name`, creates the state dir
     /// if absent, writes the file 0600, and chowns it to the agent so the