* feat(reload): add SSE live-reload server module
Problem: HTML output from pandoc has no live-reload; the browser must
be refreshed manually after each compile.
Solution: add lua/preview/reload.lua — a minimal SSE-only TCP server.
start() binds 127.0.0.1:5554 and keeps EventSource connections alive;
broadcast() pushes a reload event to all clients; inject() appends an
EventSource script before </body> (or at EOF) on every compile so
pandoc overwrites do not lose the tag.
* refactor(presets): add reload field, remove synctex field
Problem: the synctex field only handled PDF forward search and left
HTML live-preview and typst watch mode unsupported.
Solution: add reload = function(ctx) returning { 'typst', 'watch',
ctx.file } to typst (long-running watch mode), reload = true to
markdown and github (SSE push after each pandoc compile), and remove
synctex = true from latex (the -synctex=1 arg in latex.args remains
for .synctex.gz generation).
* refactor(init): replace synctex field and validation with reload
Problem: ProviderConfig still declared synctex and validated it, but
the field is being dropped in favour of the general-purpose reload.
Solution: replace the synctex annotation and vim.validate call with the
reload field, accepting boolean | string[] | function.
* feat(compiler): support long-running watch processes and SSE reload
Problem: compile() only supports one-shot invocations, requiring a
BufWritePost autocmd for watch mode and leaving HTML without live-
reload.
Solution: resolve_reload_cmd() maps provider.reload (function or table)
to a command; when present, compile() spawns it as a long-running
process instead of building a one-shot cmd from provider.cmd + args.
toggle() detects long-running providers and toggles the process
directly instead of registering a BufWritePost autocmd. When
reload = true and output is .html, the SSE server is invoked after
each successful compile. status() reports is_reload processes as
watching, not compiling. stop_all() also stops the SSE server.
* fix(compiler): format is_longrunning and annotate is_reload field
Problem: stylua required is_longrunning to be on one line; lua-ls
warned about undefined field is_reload on preview.Process.
Solution: inline the boolean expression and add is_reload? to the
preview.Process annotation.
* refactor: rename compile/toggle commands to build/watch
Problem: `compile` and `toggle` are accurate but unintuitive — `compile`
sounds academic and `toggle` says nothing about what it toggles.
Solution: rename the public API and `:Preview` subcommands to `build`
(one-shot) and `watch` (live preview). Internal compiler functions are
unchanged. No aliases for old names — clean break.
Problem: :Preview toggle gave no feedback, leaving the user to guess
whether watching was enabled or disabled.
Solution: emit vim.notify messages when toggling on ("watching with
\"<provider>\"") and off ("watching stopped"). Also normalize the
[preview.nvim] prefix in commands.lua to include the colon.
Problem: after closing a viewer, there was no way to re-open the last
compiled output without recompiling.
Solution: track the most recent output file per buffer in a `last_output`
table that persists after compilation finishes. Add `compiler.open()`,
`M.open()`, and wire it into the command dispatch.
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.
