Clear cargo warnings: drop v2.1 classifier scaffold, annotate tool_router

Three of the four dead-code warnings (`ClassifierHint`, `PolicyClassifier`,
`NoopClassifier`) were the v2.1 classifier scaffold sitting unused since
PR-1. Deleted — being unused for weeks was a stronger "no concrete plan"
signal than its presence was a "TODO" signal. Trivial to re-add when we
actually do the classifier (v0.4.0 candidate).

Fourth warning was rmcp's `#[tool_router]` macro generating internal
references to a `tool_router` field on TileService that rustc's dead-code
pass can't see through. Added `#[allow(dead_code)]` with a brief comment
on why.

`cargo build` is now clean of the four standing dead-code warnings.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memory.md

@@ -52,6 +52,16 @@ Durable memory for this project. Read at session start, update before session en
 
 ## Session log
 
+### 2026-05-26 — Clear cargo warnings: drop v2.1 classifier scaffold, annotate rmcp tool_router
+
+Four pre-existing dead-code warnings out of every cargo build. Three were the v2.1 classifier scaffold sitting unused in `mcp_policy.rs` (`ClassifierHint` enum, `PolicyClassifier` trait, `NoopClassifier` struct + impl). Deleted — the scaffold being unused for weeks was a stronger "no plan" signal than its presence was a "TODO" signal. If we actually want classifier upgrade-on-Ask later (v0.4.0 candidate), trivial to re-add; the design questions (Anthropic vs Ollama, API key UX, monthly cost cap, privacy disclosure) need a focused session.
+
+Fourth warning was rmcp's `#[tool_router]` macro generating internal references to a `tool_router: ToolRouter<Self>` field on `TileService` that rustc's dead-code pass can't see through. Added `#[allow(dead_code)]` to the field with a comment explaining why.
+
+`cargo build` is now clean (modulo any new bugs).
+
+Open follow-up: v0.4.0 classifier ([[v2.1-classifier]]). Design notes for that session — pick Haiku 4.5 via Anthropic API as default; API key in Windows Credential Manager (matches SSH password storage, doesn't sync); 60s cache by `(tool, args_repr)`; classifier can only upgrade Ask → Allow, never downgrade.
+
 ### 2026-05-26 — Backed out idle "claude foreground" filter (kept legacy 5s notify)
 
 Shipped earlier today as per-distro, pivoted to per-pane via `TILETOPIA_PANE_ID` env marker, then a probe-script bug surfaced (positional args dropped by `wsl.exe -- bash -c "..." _ <id>`). Fixed the arg-passing by inlining values, but on real-app test the pane still showed idle while claude was running — and at that point the user (rightly) called credit waste and asked to back the whole feature out.

src-tauri/src/mcp.rs

@@ -301,6 +301,10 @@ pub struct TileService {
     pending: Arc<PendingActions>,
     rate_limiter: Arc<WriteRateLimiter>,
     app: AppHandle,
+    // Used by the code rmcp's `#[tool_router]` macro generates; rustc's
+    // dead-code pass can't see through the macro, hence the explicit
+    // suppression rather than a redesign.
+    #[allow(dead_code)]
     tool_router: ToolRouter<Self>,
 }
 

src-tauri/src/mcp_policy.rs

@@ -67,30 +67,6 @@ pub enum PolicyDecision {
     Deny { reason: String, hard: bool },
 }
 
-// ---------------------------------------------------------------------------
-// Classifier hook (scaffold — no-op default; v2.1 will wire into evaluate)
-// ---------------------------------------------------------------------------
-
-pub enum ClassifierHint {
-    Allow,
-    Ask,
-}
-
-pub trait PolicyClassifier: Send + Sync {
-    /// Called for tool calls that fall through to Ask. Returns a hint that
-    /// may upgrade the decision to Allow (skipping the confirmation prompt)
-    /// or stay at Ask. Errors leave the decision unchanged.
-    fn classify(&self, tool: &str, args_repr: &str) -> Result<ClassifierHint, anyhow::Error>;
-}
-
-pub struct NoopClassifier;
-
-impl PolicyClassifier for NoopClassifier {
-    fn classify(&self, _tool: &str, _args_repr: &str) -> Result<ClassifierHint, anyhow::Error> {
-        Ok(ClassifierHint::Ask)
-    }
-}
-
 // ---------------------------------------------------------------------------
 // Hard-deny patterns (compiled-in, non-overridable)
 // ---------------------------------------------------------------------------