simplify nixos module

simplify config check

use only one handler function with arguments

fetch calendar as background task

remove old single-calendar configuration from example

reload nix shell when pyproject.toml changes

replace flask and gunicorn with quart and uvicorn

remove backwards compatibility

output only one event when two have matching times

add config example

allow multiple calendars with override of tentative detection

always return UTC times to avoid vTimezone requirement

make output conform to spec (aside from vTimezone)

ensure python can access zoneinfo database

set correct content-type header

use same timezone as input calendar

encode dtstamp differently for go compatibility

allow webcal:// scheme to be used in configuration

export free/busy components instead of events

log errors to console

refactor to ease multi-calendar implementation

output free/busy components instead of events

preserve UIDs from main calendar

add justfile

delete poetry lockfile

use specific route for ics format

start from beginning of week

fix startup failing when run via nixos module

feat: load configuration from TOML file for calendar settings

fix nix devshell

fix nixos module file/url types

initial commit