maarcadetweet: initial commit

AT Protocol PDS + AppView + Tauri Desktop Client, 160-char post limit.

- PDS (Rust + axum + sqlx)
  - Auth: createAccount, createSession, refreshSession
  - Records: createRecord, deleteRecord (race-safe via SELECT FOR UPDATE)
  - Feed: feed.like.create, feed.repost.create
  - Sync: getRepo, getBlocks, getLatestCommit, getRecord (with MST proof), listRepos
  - Identity: resolveHandle
  - MST: spec-conformant (at-mst crate, 27 tests)
  - Repo: signed commits, TID counter (monotonic, 4096 wrap safe)

- AppView (Rust + axum + sqlx)
  - Jetstream consumer (WebSocket, exponential backoff, 38k+ events indexed)
  - REST API: timeline/home (graph-aware), profile, search, post (with thread hydration)
  - Handle-sync worker (did:plc + did:web)
  - JSONB embed storage + thread columns (migration 0003)
  - Like/repost counter cache (migration 0004)

- Tauri 2 + Svelte 5 Desktop Client
  - System tray (Show/Compose/Quit menu)
  - OS notifications (tauri-plugin-notification)
  - Auto-update (tauri-plugin-updater, placeholder endpoint)
  - Window-state (tauri-plugin-window-state)
  - 160-char compose with live counter
  - Image/Link embed rendering
  - LocalStorage-persisted like state
  - Timeline with poll (prepend new posts)
  - Custom TitleBar (transparent, no decorations)
  - Orange/IBM Plex Mono maarcade design

Tests: 231 Rust + 9 vitest = 240 passed.

Cargo.toml

@@ -0,0 +1,90 @@
+[workspace]
+resolver = "2"
+members = [
+  "crates/at-lexicon",
+  "crates/at-crypto",
+  "crates/at-identity",
+  "crates/at-mst",
+  "crates/at-repo",
+  "crates/at-blob",
+  "crates/at-firehose",
+  "crates/at-shared",
+  "crates/pds-server",
+  "crates/appview",
+]
+
+[workspace.package]
+version = "0.1.0"
+edition = "2021"
+license = "EUPL-1.2"
+authors = ["EifelCloud"]
+rust-version = "1.80"
+
+[workspace.dependencies]
+tokio = { version = "1", features = ["full"] }
+axum = "0.7"
+tower = "0.5"
+tower-http = { version = "0.6", features = ["cors", "trace", "compression-gzip"] }
+hyper = "1"
+sqlx = { version = "0.8", features = ["runtime-tokio", "postgres", "macros", "uuid", "chrono", "json", "migrate"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+serde_cbor_2 = "0.12"
+ciborium = "0.2"
+uuid = { version = "1", features = ["v4", "serde"] }
+chrono = { version = "0.4", features = ["serde"] }
+utoipa = { version = "5", features = ["axum_extras", "uuid", "chrono"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter", "json"] }
+anyhow = "1"
+thiserror = "2"
+argon2 = "0.5"
+async-trait = "0.1"
+reqwest = { version = "0.12", features = ["json", "stream", "multipart"] }
+k256 = { version = "0.13", features = ["ecdsa", "sha256", "serde"] }
+p256 = { version = "0.13", features = ["ecdsa", "sha256", "serde", "pem", "pkcs8"] }
+sec1 = "0.7"
+secp256k1 = { version = "0.29", features = ["rand", "serde"] }
+jsonwebtoken = "9"
+cid = { version = "0.11", features = ["serde"] }
+multibase = "0.9"
+multihash = "0.19"
+sha2 = "0.10"
+blake3 = "1"
+rand = "0.8"
+rand_core = "0.6"
+hex = "0.4"
+base64 = "0.22"
+parking_lot = "0.12"
+async-stream = "0.3"
+http = "1"
+http-body-util = "0.1"
+bytes = "1"
+futures = "0.3"
+tokio-stream = { version = "0.1", features = ["sync"] }
+tokio-tungstenite = { version = "0.24", features = ["rustls-tls-webpki-roots"] }
+url = "2"
+dashmap = "6"
+rusqlite = { version = "0.32", features = ["bundled"] }
+tempfile = "3"
+insta = { version = "1", features = ["yaml"] }
+infer = "0.16"
+
+at-shared = { path = "crates/at-shared" }
+at-crypto = { path = "crates/at-crypto" }
+at-lexicon = { path = "crates/at-lexicon" }
+at-identity = { path = "crates/at-identity" }
+at-mst = { path = "crates/at-mst" }
+at-repo = { path = "crates/at-repo" }
+at-blob = { path = "crates/at-blob" }
+at-firehose = { path = "crates/at-firehose" }
+
+[profile.release]
+lto = "thin"
+codegen-units = 1
+strip = true
+opt-level = 3
+
+[profile.dev]
+opt-level = 0
+debug = 1