Upgrade workspace to edition 2024, add --local flag to agent run

Edition 2024 changes:
- gen is reserved: rename variable in query/engine.rs
- set_var is unsafe: wrap in unsafe block in cli/agent.rs
- match ergonomics: add explicit & in spectral.rs filter closure

New --local flag for `poc-memory agent run` bypasses the daemon and
runs the agent directly in-process. Useful for testing agent prompt
changes without waiting in the daemon queue.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-memory/Cargo.toml

@@ -21,6 +21,8 @@ peg = "0.8"
 paste = "1"
 jobkit = { git = "https://evilpiepirate.org/git/jobkit.git/" }
 jobkit-daemon = { git = "https://evilpiepirate.org/git/jobkit-daemon.git/" }
+reqwest = { version = "0.12", features = ["blocking", "json"] }
+poc-agent = { path = "../poc-agent" }
 redb = "2"
 log = "0.4"
 ratatui = "0.29"