refactor: eradicate deprecated tools (sticky_notes, pinned_files, context_workspaces, pr_checklist, preferences) and dead code

ARCHITECTURE_RESOURCES_PROMPTS.md

@@ -71,7 +71,7 @@ pub trait McpPrompt: Send + Sync {
 
 ## 4. Execution Plan
 1. **Refactor `router.rs` (No functional changes yet):** Define the `McpResource` and `McpPrompt` traits. Update the `MemoryHandler` struct to hold these HashMaps. Migrate the existing hardcoded stubs (`memory://graph/entities` and `analyze_tech_debt`) into structs implementing these traits.
-2. **Expand Resources (Phase 1):** Add new handlers for `memory://tasks/active`, `memory://pinned_files`, etc.
+2. **Expand Resources (Phase 1):** Add new handlers for `memory://tasks/active`, `memory://session/delta`, etc.
 3. **Expand Prompts (Phase 2):** Add new handlers for `handoff_routine`, etc.
 
 This design guarantees we do not needlessly tear up code—we merely extend the existing robust `McpTool` pattern to the rest of the protocol.