veiland 0.2.0

veiland 0.2.0

Veiland gains a Python plugin tier: a full SDK plus nine ready-made
widgets, so a scene can now show the weather, what's playing, or your
network state without writing Rust. Wallpapers can blur, plugins can be
anchored to a corner instead of pinned to pixel coordinates, and the
text tier moved to Pango markup.

Upgrading from 0.1.0: read Removed and Changed first. The
clock and label plugins are gone, and PAM no longer runs the account
phase.

Added

Python plugin tier

• veiland_plugin.py, a Python SDK mirroring the Rust one: wire codec,
  Connection, GBM buffer allocation, FramePacer, and BufferChain.
  Plugins are ordinary Python programs; the wire format was never tied
  to Rust, and this is the proof.
• Four companions: veiland_text (Pango text), veiland_svg (SVG icon
  rendering), veiland_dbus (D-Bus, no async runtime), and
  veiland_layout (content anchoring and debug borders).
• Nine widgets installed as veiland-* commands on every packaging
  target: markup, weather, now-playing, avatar, wifi,
  ethernet, bluetooth, battery, shape.
• markup is the new text tier: one block of Pango markup with ten
  substitutions: {user}, {name}, {host}, {time}, {date},
  {uptime}, {loadavg}, {kernel}, {distro}, {distro_version}.
  {time} and {date} take a strftime format; a bad one shows the text
  you typed instead of crashing.
• weather reads Open-Meteo by city name or latitude/longitude. No API
  key, and the fetch uses only the standard library, so it adds no
  dependency beyond the shared widget stack. Eleven CC0 icons included.
• now-playing shows the current MPRIS track, read-only.
• shape draws a rounded colored rectangle, a backdrop to group other
  widgets against.
• Python tooling in CI: ruff, mypy --strict, and pytest.

Core

• Anchored region placement: halign/valign with fraction-of-surface
  width, height, and margin (margin_x/margin_y per axis). A
  widget anchored to a corner lands in the same relative spot on 1080p
  and 4K, instead of at fixed pixel coordinates.
• --help and --version. Version carries the git revision on builds
  off master, so a bug report says which build it came from.
• VEILAND_GL_DEBUG=1 for GL diagnostics: the driver debug callback
  where available, with a glGetError fallback.

Plugins

• wallpaper gained blur, darken, and blur_regions: blur the
  whole surface, then tint rounded regions on top as frosted cards.
• particles gained an opt-in twinkle (with twinkle_speed and
  twinkle_depth) for a shimmering starfield.
• Optional labels beside the glyph on wifi, bluetooth, and
  battery; avatar gained a rounded-square shape.

Scenes and docs

• Four composed example scenes with screenshots: aurora-corners,
  aurora-card, aurora-dashboard, and deepfield.
• A documentation website (Zola), with per-plugin reference pages
  generated from a single source and checked in CI.
• docs/plugin-python.md, the Python SDK reference.
• Manual VM packaging tests (scripts/vmtest/) that boot real Debian,
  Fedora, and Arch guests, install the built package, and verify the
  widget dependency closure resolves.

Changed

• PAM now runs pam_authenticate only, not pam_acct_mgmt. A
  correct password was intermittently rejected right after a fast logout
  and login, because the account phase returned a transient error while
  logind tore down the previous session. A locker re-verifies an
  existing session; deciding whether an account may start one is a
  login manager's job, and applying it here could lock you out of your
  own live session with no way to change the password. Shipped PAM files
  drop the now-dead account line. Existing installs keep their current
  file, where the stale line is simply never evaluated. Trade-off: an
  account disabled while the screen is locked still unlocks with a
  correct password. The session is already open either way.
• Configure now carries the plugin's region dimensions rather than the
  full surface size, so a plugin assigned a region renders at that
  region's size instead of drawing full-surface and being squashed into
  it.
• Python widgets are referenced by bare veiland-* name in the example
  scenes, resolved on PATH like the Rust plugins.

Removed

• The clock and label plugins. markup replaces both, with
  Pango markup, live substitutions, and font matching that follows the
  system's configuration. Scenes using them need
  binary = "veiland-markup" and a text key; see
  docs/examples/ for worked configurations.

Fixed

• CPU-rendered plugins flickered because a single buffer was redrawn in
  place while the host was still sampling it. BufferChain double-buffers
  and fixes it.
• Dmabufs that a driver only accepts as external textures rendered black
  (NVIDIA marks linear and CPU-written buffers this way, so every CPU
  plugin was affected). The core now samples them via
  GL_TEXTURE_EXTERNAL_OES, and falls back cleanly on stacks without the
  extension.
• Glyphs bled into their neighbours in the text atlas; a 1px gutter fixes
  it.
• A glyph the rasterizer can't render is now reported once instead of
  silently vanishing. Hairline font weights drop digits on some fonts,
  which previously looked like a bug in the clock.