scoring: drop dead Elo/agent_budget block in consolidation_plan

The graph-health logic in consolidation_plan_inner computed
reasonable agent counts based on graph metrics (α, Gini, hub
dominance), then immediately overwrote them with an Elo-weighted
flat-budget distribution, or — if no agent-elo.json existed —
with a simple budget/N per type.

Nothing in the codebase writes agent-elo.json; it's external state
that never gets maintained. So the effective behavior was always the
"No Elo ratings — equal distribution" branch, which just bucketed
agent_budget evenly across active agent types and discarded
everything the graph analysis had just decided.

Keep the graph-health allocation (α → linker count, Gini → distill
bump, organize/distill/split proportional). Drop:

- The entire Elo / agent_budget block at the end of
  consolidation_plan_inner
- Config.agent_budget field and its default (1000)
- agent_budget: 40 from Kent's config.json5
- The local agent_types binding inside the function — it was only
  used by the now-deleted block. Config.agent_types stays; it has
  other consumers.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/config.rs

@@ -58,7 +58,6 @@ pub struct Config {
     #[serde(default)]
     pub agent_nodes: Vec<String>,
     pub llm_concurrency: usize,
-    pub agent_budget: usize,
     /// Stream chunk timeout in seconds (no data = timeout).
     #[serde(default = "default_stream_timeout")]
     pub api_stream_timeout_secs: u64,
@@ -101,7 +100,6 @@ impl Default for Config {
             personality_nodes: vec!["identity".into(), "core-practices".into()],
             agent_nodes: vec!["identity".into(), "core-practices".into()],
             llm_concurrency: 1,
-            agent_budget: 1000,
             api_stream_timeout_secs: default_stream_timeout(),
             scoring_interval_secs: default_scoring_interval_secs(),
             scoring_response_window: default_scoring_response_window(),