Phase 1 — Foundation

Mirror NPE's dependency-free spine in Rust:

* exceptions   — NetworkError + ParsingError + ContentUnavailable
                 + ExtractionError tree, with reqwest/serde_json conversions
* localization — Localization + ContentCountry, default (en, GB)
* downloader/  — Downloader trait, Request builder, Response,
                 reqwest blocking default impl
* page         — continuation-token carrier
* image        — Image + ImageSet + ResolutionLevel
                 (HEIGHT_UNKNOWN/WIDTH_UNKNOWN = -1)
* metainfo     — title/content/url/url_text grab-bag
* service      — StreamingService trait + LinkType + ServiceInfo
* newpipe      — process-global Downloader / Localization /
                 ContentCountry singleton

Foundational invariants nailed down (per SPEC §3):
* HTTP non-2xx returns Ok(Response); only 429 throws NetworkError::Recaptcha
* Response header keys lowercase-normalized
* Request.add_header PARITY with NPE bug (silent overwrite);
  append_header is our clean addition
* default Localization is en-GB
* No cookie jar in the default downloader

Tests: 7 unit + 7 live smoke against httpbin.org (gated on
'online-tests' feature). All green.

Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name = "strawcore"
+version = "0.1.0"
+edition = "2021"
+license = "GPL-3.0-or-later"
+authors = ["Sulkta"]
+repository = "https://git.sulkta.com/Sulkta-OSS/strawcore"
+description = "Rust port of NewPipeExtractor (YT-only). Plugs into Straw via UniFFI."
+
+[lib]
+crate-type = ["rlib", "cdylib", "staticlib"]
+
+[dependencies]
+reqwest = { version = "0.12", default-features = false, features = ["rustls-tls-webpki-roots", "blocking", "gzip"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+thiserror = "1"
+parking_lot = "0.12"
+url = "2"
+once_cell = "1"
+
+[dev-dependencies]
+serde_json = "1"
+
+[features]
+default = []
+# `online-tests` gates network-dependent integration tests. Enable with
+# `cargo test --features online-tests` once an internet route is available.
+online-tests = []
+
+[profile.release]
+strip = true
+lto = "thin"
+codegen-units = 1
+panic = "abort"
+opt-level = "z"
+
+[profile.dev]
+opt-level = 0
+debug = 1