* refactor: rename build to compile and watch to toggle in public API
Problem: the code used build/watch while the help file already
documented compile/toggle, creating a confusing mismatch.
Solution: rename M.build() to M.compile() and M.watch() to M.toggle()
in init.lua, update handler keys in commands.lua, and update the test
file to match.
* refactor(commands): make toggle the default subcommand
Problem: bare :Preview ran a one-shot compile, but users reaching for a
"preview" plugin expect it to start previewing (i.e. watch mode).
Solution: change the fallback subcommand from compile to toggle so
:Preview starts/stops auto-compile on save.
* refactor(commands): remove stop subcommand
Problem: :Preview stop had a subtle distinction from toggle-off (kill
process but keep autocmd) that nobody reaches for deliberately from
the command line.
Solution: remove stop from the command dispatch table. The Lua API
require('preview').stop() remains as a programmatic escape hatch.
* docs: update help file for new command surface and document reload
Problem: the help file listed compile as the default subcommand, still
included the stop subcommand, omitted the reload provider field, and
had a misleading claim about shipping with zero defaults.
Solution: make toggle the default in the commands section, remove stop
from subcommands, add reload to provider fields, fix the introduction
text, reorder API entries to match new primacy, and add an output path
override example addressing #26/#27.
* refactor(config): replace array preset syntax with preset_name = true
Problem: setup() mixed array entries (preset names) and hash entries
(custom providers keyed by filetype), requiring verbose
vim.tbl_deep_extend boilerplate to override presets.
Solution: unify under a single key=value model. Keys are preset names
or filetypes; true registers the preset as-is, a table deep-merges
with the matching preset (or registers a custom provider if no preset
matches), and false is a no-op. Array entries are dropped. Also adds
-f gfm to presets.github args so pandoc parses input as GFM.
* ci: format
* fix(presets): parenthesize gsub output to suppress redundant-return-value
* ci: remove superfluous things
* refactor: remove PreviewWatch* events and clean up docs
Problem: PreviewWatchStarted/PreviewWatchStopped were redundant with
the status() API, and the doc had a wrong author, stale INSTALLATION
format, and "watch mode" language left over from the watch → toggle
rename.
Solution: Remove the events and their tests. Fix the doc author,
rename INSTALLATION → SETUP to match sibling plugins, replace "watch
mode" with "auto-compile" throughout, and drop the events from EVENTS.
* refactor(config): replace array preset syntax with preset_name = true
Problem: setup() mixed array entries (preset names) and hash entries
(custom providers keyed by filetype), requiring verbose
vim.tbl_deep_extend boilerplate to override presets.
Solution: unify under a single key=value model. Keys are preset names
or filetypes; true registers the preset as-is, a table deep-merges
with the matching preset (or registers a custom provider if no preset
matches), and false is a no-op. Array entries are dropped. Also adds
-f gfm to presets.github args so pandoc parses input as GFM.
* ci: format
* fix(presets): parenthesize gsub output to suppress redundant-return-value
Problem: :Preview watch only registered a BufWritePost autocmd without
compiling immediately, required boilerplate to open output files after
first compilation, and was misleadingly named.
Solution: Rename watch → toggle throughout. M.toggle now compiles
immediately on activation. Add an open field to ProviderConfig: true
calls vim.ui.open(), a string[] runs the command with the output path
appended, tracked per-buffer so the file opens only once. All presets
default to { 'xdg-open' }. Health check validates opener binaries.
Guard the async compile callback against invalid buffer ids.
