feat: vector graphics, PSP SDI integration, and streaming video decode

CLAUDE.md

@@ -4,7 +4,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Project Overview
 
-OASIS_OS is an embeddable operating system framework in Rust (edition 2024). It provides a skinnable shell with a scene-graph UI, command interpreter, virtual file system, browser engine (HTML/CSS/Gemini), plugin system, and remote terminal. It renders to any pixel buffer + input stream. Originally ported from a PSP homebrew shell (2006-2008). Seventeen skins are implemented (11 external TOML skins, 17 built-in; external skins also have built-in equivalents).
+OASIS_OS is an embeddable operating system framework in Rust (edition 2024). It provides a skinnable shell with a scene-graph UI, command interpreter, virtual file system, browser engine (HTML/CSS/Gemini), plugin system, and remote terminal. It renders to any pixel buffer + input stream. Originally ported from a PSP homebrew shell (2006-2008). Eighteen skins are implemented (12 external TOML skins, 18 built-in; external skins also have built-in equivalents).
 
 Default virtual resolution is 480x272 (PSP native). Skins may override this (e.g. modern=800x600, xp=1024x768); the backend canvas/window scales to match.
 
@@ -88,6 +88,7 @@ oasis-types     (foundation: Color, Button, InputEvent, backend traits, error ty
 ├── oasis-browser    (HTML/CSS/Gemini: DOM, CSS cascade, layout engine, JS DOM bindings)
 ├── oasis-js         (JavaScript engine: QuickJS-NG runtime, console API)
 ├── oasis-video      (MP4/H.264+AAC decode; features: h264, no-std-demux, video-decode)
+├── oasis-vector     (vector graphics: scene graph, path ops, icons, frame-driven animations)
 └── oasis-core       (coordination: 16 apps, dashboard, agent, plugin, script)
     ├── oasis-backend-sdl  (SDL2 desktop/Pi rendering + input + audio)
     │   └── oasis-app      (binary entry points: oasis-app, oasis-screenshot; oasis-video[video-decode])
@@ -106,11 +107,30 @@ The PSP deployment uses two binaries:
 
 The PRX hooks `sceDisplaySetFrameBuf` to draw overlay UI into the game's framebuffer and claims a PSP audio channel for background MP3 playback. No dependency on oasis-core -- direct framebuffer rendering only (<64KB binary).
 
+### PSP TLS 1.3
+
+The PSP firmware's built-in SSL uses root CAs from 2008 and SSL 3.0, which cannot connect to modern HTTPS servers. The PSP backend implements native TLS 1.3 via `embedded-tls` (pure Rust, no C/asm) with `UnsecureProvider` (no certificate validation). The `alloc` feature is required to advertise RSA signature schemes (archive.org uses RSA certs). Raw TCP sockets (`sceNetInet*`) are wrapped with `embedded_io::Read + Write` adapters. RNG seeded from `sceKernelGetSystemTimeLow` (not `mfc0 $9` which is privileged on PSP Allegrex). DNS resolution via `psp::net::resolve_hostname` with `to_ne_bytes()` (network byte order fix for little-endian MIPS). HTTP→HTTPS redirect loops are detected automatically, triggering TLS fallback; HTTPS redirects (archive.org → CDN node) are followed within the TLS path. This enables HTTPS downloads for TV Guide video streaming from servers that enforce TLS.
+
+### PSP Video Streaming
+
+TV Guide on PSP uses in-memory streaming (no disk I/O). The I/O thread downloads HTTP(S) data, buffers the MP4 `moov` atom (~1-3MB), parses track tables via `demux_lite::Mp4Lite`, then extracts interleaved audio/video samples from the `mdat` stream in file-offset order. Video samples are skipped (H.264 decode requires real ME hardware, not available on PPSSPP). Audio AAC frames are decoded via `sceAudiocodec` hardware and output through `AudioChannel::output_blocking`. Backpressure is applied via retry-with-sleep when the audio command queue is full, naturally throttling the download to real-time playback speed.
+
+### Desktop Video Streaming
+
+TV Guide on desktop uses in-process progressive streaming via `StreamingBuffer` (in `tv_controller.rs`). A background download thread feeds an `Arc<StreamingInner>` sliding-window buffer while symphonia decodes from the same buffer via `Read + Seek`. Key mechanisms:
+
+- **`probe_mode`** — During symphonia's probe phase, reads return zeros so mdat body is skipped instantly. `decoder_pos` is NOT updated during probe to prevent a throttle deadlock.
+- **Deferred tail probe** — A separate thread fetches the last 8MB for moov-at-end files, but only launches after >8MB body data received without finding moov. Prevents CDN connection throttling.
+- **`should_throttle()`** — Backpressure: `decoder_pos > 0 ? received > decoder_pos + 16MB : has_moov && buf_size > 16MB`
+- **CDN failover** — Range requests route through the original archive.org URL (not cached CDN) to get a fresh 302 redirect, avoiding 401 errors from stale CDN nodes. `open_range_connection()` follows redirect chains.
+- **Prebuffer gate** — Decoder waits for MIN_PREBUFFER (2MB) of body data before seeking, preventing reads into empty buffer regions.
+- **Seek restart** — After probe discovers moov, the download restarts from the estimated byte offset via a Range request. Linear interpolation: `(seek_secs / duration) * file_size`.
+
 ### Key Abstraction: Backend Traits
 
 `oasis-types/src/backend.rs` defines the only abstraction boundary between core and platform (re-exported by `oasis-core`):
 - `SdiCore` -- required rendering (13 methods: init, clear, blit, fill_rect, draw_text, swap_buffers, load_texture, destroy_texture, set_clip_rect, reset_clip_rect, measure_text, read_pixels, shutdown)
-- `SdiBackend` -- extends `SdiCore` with 30 optional accelerated primitives (shapes, gradients, text styling, batching)
+- `SdiBackend` -- extends `SdiCore` with 30+ optional accelerated primitives (shapes, gradients, text styling, batching, vector graphics path operations)
 - `InputBackend` -- input polling (returns `Vec<InputEvent>`)
 - `NetworkBackend` -- TCP networking
 - `AudioBackend` -- audio playback
@@ -119,11 +139,11 @@ Core code never calls platform APIs directly. All platform interaction goes thro
 
 ### Core Modules
 
-The framework is split into 19 workspace crates. Each module below is its own crate (previously all in oasis-core):
+The framework is split into 20 workspace crates. Each module below is its own crate (previously all in oasis-core):
 
 - **oasis-types** -- Foundation types: `Color`, `Button`, `InputEvent`, backend traits (`SdiCore`, `SdiBackend`, `InputBackend`, `NetworkBackend`, `AudioBackend`), error types, TLS, bitmap font metrics
 - **oasis-sdi** -- Scene Display Interface: named objects with position, size, color, texture, text, z-order, gradients, rounded corners, shadows
-- **oasis-skin** -- Data-driven TOML skin system with 17 skins (11 external TOML in `skins/`, 17 built-in). Theme derivation from 9 base colors.
+- **oasis-skin** -- Data-driven TOML skin system with 18 skins (12 external TOML in `skins/`, 18 built-in). Theme derivation from 9 base colors.
 - **oasis-browser** -- Embeddable HTML/CSS/Gemini rendering engine: DOM parser, CSS cascade, block/inline/table layout, link navigation, reader mode, JavaScript DOM bindings
 - **oasis-js** -- JavaScript engine wrapping QuickJS-NG via rquickjs: `console` API (log/warn/error/info), inline `<script>` execution, DOM manipulation (`document.getElementById`, `createElement`, `textContent`, attributes). Feature-gated (`javascript`)
 - **oasis-ui** -- 27 reusable widgets: Button, Card, TabBar, Panel, TextField, ListView, ScrollView, ProgressBar, Toggle, NinePatch, flex layout, Accordion, Avatar, Badge, Checkbox, Dropdown, Modal, Slider, Spinner, Toast, Tooltip, TreeView, and more
@@ -133,7 +153,8 @@ The framework is split into 19 workspace crates. Each module below is its own cr
 - **oasis-net** -- TCP networking with PSK authentication, remote terminal, FTP transfer
 - **oasis-audio** -- Audio manager with playlist, shuffle/repeat modes, MP3 ID3 tag parsing
 - **oasis-platform** -- Platform service traits: PowerService, TimeService, UsbService, NetworkService, OskService
-- **oasis-video** -- MP4/H.264+AAC decode pipeline. Feature flags: `h264` (openh264 video decode + symphonia demux/AAC), `no-std-demux` (lightweight `demux_lite::Mp4Lite` parser, no symphonia/no std::sync::Once — PSP-safe), `video-decode` (re-exports `SoftwareVideoDecoder` for desktop/UE5). Streaming pipelines: desktop downloads MP4 then decodes in-process with PTS-based A/V sync; PSP uses `demux_lite` + `sceAudiocodec` AAC hardware decode + `sceVideocodec` H.264 (real HW only, audio-only on PPSSPP)
+- **oasis-video** -- MP4/H.264+AAC decode pipeline. Feature flags: `h264` (openh264 video decode + symphonia demux/AAC), `no-std-demux` (lightweight `demux_lite::Mp4Lite` parser, no symphonia/no std::sync::Once — PSP-safe), `video-decode` (re-exports `SoftwareVideoDecoder` for desktop/UE5). Streaming pipelines: desktop uses `StreamingBuffer` sliding-window for progressive playback with deferred tail probe, CDN failover, and PTS-based A/V sync; PSP streams in-memory via `demux_lite` + `sceAudiocodec` AAC hardware decode + `sceVideocodec` H.264 (real HW only, audio-only on PPSSPP) with backpressure-throttled I/O
+- **oasis-vector** -- Resolution-independent vector graphics: scene graph with path-based drawing operations (fill, stroke, arcs, beziers), Altimit-style dashboard icons, and frame-driven animations. Integrates via `SdiBackend` vector graphics trait extensions
 - **oasis-core** -- Coordination layer: app runner with 16 apps (File Manager, Settings, Network, Music Player, Photo Viewer, Package Manager, Browser, System Monitor, TV Guide, Internet Radio, Terminal, Text Editor, Calculator, Clock, Paint, Games), dashboard, agent/MCP, plugin, scripting, status/bottom bars
 
 ### Font Rendering