feat: add db and multi-archive web UI foundation (#8)

* Add SQLite metadata database support

* Implement archive metadata database

* chore: let's guess cargoHash because there's something wrong with nixpkgs!

* Gate test-only database helpers behind cfg(test)

* Fix archive database row identity

* Use serde for archive metadata JSON

* Finalize archive runs at command level

* Handle archive command errors without panics

* Cover tweet entry metadata recording

* Document static regex invariants

* docs: add web UI design spec

* docs: add web UI implementation plan

* chore: move cli into workspace crate

* chore: track workspace crates directory

* refactor: extract archive core crate

* refactor: add core archive opening APIs

* refactor: rename taxonomy model to tags

* feat: add archive query APIs

* feat: add web server registry

* feat: expose archive server APIs

* feat: add archive table web UI

* fix: complete web UI smoke path

* docs: add architecture mental model

* docs: remove private superpowers plans

* nix: split cli and server packages

* chore: remove PLAN.md

src/twitter.rs

@@ -1,8 +0,0 @@
-/// Returns the tweet ID if `id` is non-empty and contains only ASCII digits.
-pub fn parse_tweet_id(id: &str) -> Option<String> {
-    if !id.is_empty() && id.chars().all(|char| char.is_ascii_digit()) {
-        Some(id.to_string())
-    } else {
-        None
-    }
-}