Move SPEC.md to development/ and rewrite as a technical reference

The old spec was a 1426-line forward-looking planning doc (phases,
pending decisions, design sketches for work now shipped). Replace it
with a concise 339-line reference describing the implemented system —
architecture, AST, LSP capabilities + executeCommand surface, editor
integration, config schema, keymaps, syntax support, and CI — verified
against the current code. Lives under development/ with the other
developer-only docs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

development/ONBOARDING.md

@@ -70,6 +70,7 @@ nuwiki/
 │
 ├── development/                # Developer-only tooling and docs (not shipped)
 │   ├── ONBOARDING.md           # This file
+│   ├── SPEC.md                 # Technical reference (architecture, LSP, commands)
 │   ├── nuwiki-architecture.html
 │   ├── start-nvim.sh           # Launch Neovim against a generated sample wiki
 │   ├── start-vim.sh            # Launch Vim against a generated sample wiki

development/SPEC.md

@@ -0,0 +1,339 @@
+# nuwiki — Technical Reference
+
+A developer-facing description of how nuwiki is built and what it implements.
+For day-one setup see [ONBOARDING.md](ONBOARDING.md); for user-facing help see
+`doc/nuwiki.txt` (`:h nuwiki`).
+
+nuwiki is a vimwiki-compatible Vim/Neovim plugin backed by a Rust language
+server. The editor layers are thin clients; all parsing, navigation, and
+editing logic lives in the Rust crates and is reached over LSP.
+
+| Property | Value |
+|---|---|
+| License | Dual MIT / Apache-2.0 |
+| MSRV | Rust 1.83 |
+| Edition / resolver | 2021 / v2 |
+| Repo | `https://code.gfran.co/gffranco/nuwiki` |
+| VCS / CI | Gitea + Gitea Actions |
+| LSP library | `tower-lsp` (tokio, stdio transport) |
+| Min editors | Neovim 0.11+, Vim 9.1+ |
+
+---
+
+## 1. Architecture
+
+### Layer model
+
+```
+Editor client (VimL / Lua)  — pure wiring, no logic
+        │  LSP over stdio
+        ▼
+nuwiki-lsp  — protocol bridge, executeCommand, document store, config
+        │
+        ▼
+nuwiki-core — lexer → parser → AST → renderer (no editor deps)
+```
+
+### Crate dependency rules
+
+```
+nuwiki-ls  →  nuwiki-lsp  →  nuwiki-core
+```
+
+- `nuwiki-core` never depends on `nuwiki-lsp` / `nuwiki-ls`.
+- `nuwiki-lsp` never depends on `nuwiki-ls`.
+- The VimL and Lua layers contain no logic — every command body issues a
+  `workspace/executeCommand` or a built-in LSP request.
+
+### Repository layout
+
+```
+crates/
+  nuwiki-core/        # parser, AST, renderer — editor-independent
+    src/
+      ast/            # block.rs inline.rs link.rs span.rs visit.rs
+      syntax/         # registry.rs + vimwiki/{lexer,parser}.rs
+      render/         # html.rs
+      date.rs         # diary period math (no chrono dependency)
+  nuwiki-lsp/         # LSP backend
+    src/
+      lib.rs          # Backend, capabilities, textDocument handlers
+      commands.rs     # executeCommand dispatcher + pure edit ops
+      config.rs       # Config / WikiConfig / HtmlConfig
+      diagnostics.rs index.rs nav.rs rename.rs semantic_tokens.rs
+      diary.rs export.rs edits.rs folding.rs wiki.rs
+  nuwiki-ls/          # thin binary: starts the stdio server
+
+plugin/nuwiki.vim     # universal entry point (detects Vim vs Neovim)
+lua/nuwiki/           # Neovim layer: init, config, lsp, keymaps, commands,
+                      #   folding, install
+autoload/nuwiki/      # Vim layer: lsp.vim, commands.vim
+ftdetect/ ftplugin/ syntax/   # filetype detection, buffer setup, fallback HL
+doc/nuwiki.txt        # :help
+scripts/download_bin.vim      # plugin-runtime binary download (build hooks)
+development/          # dev-only tooling + this document (not shipped)
+.gitea/workflows/     # ci.yaml, release.yaml
+```
+
+---
+
+## 2. nuwiki-core
+
+### AST
+
+Every node carries a `Span { start, end }` of `Position { line, column, offset }`
+(0-indexed; column and offset are byte-based). Spans drive diagnostics,
+semantic tokens, and go-to-definition.
+
+**Block nodes:** `Heading` (level 1–6, `centered`), `Paragraph`,
+`HorizontalRule`, `Blockquote` (recursive), `Preformatted` (optional
+language), `MathBlock` (optional environment), `List`, `DefinitionList`,
+`Table`, `Comment`, `Tag`, `Error` (resilient parse failure).
+
+**Inline nodes:** `Text`, `Bold`, `Italic`, `BoldItalic`, `Strikethrough`,
+`Code`, `Superscript`, `Subscript`, `MathInline`, `Keyword`, `Color`,
+`WikiLink`, `ExternalLink`, `Transclusion`, `RawUrl`.
+
+**Enums:**
+- `ListSymbol` = `Dash | Star | Hash | Numeric | NumericParen | AlphaParen |
+  AlphaUpperParen | RomanParen | RomanUpperParen`
+- `CheckboxState` = `Empty | Quarter | Half | ThreeQuarters | Done | Rejected`
+- `Keyword` = `Todo | Done | Started | Fixme | Fixed | Xxx | Stopped`
+- `LinkKind` = `Wiki | Interwiki | Diary | File | Local | Raw | AnchorOnly`
+- `TagScope` = `File | Heading(idx) | Standalone`
+
+`PageMetadata` carries `title`, `nohtml`, `template`, `date`, and aggregated
+file-level `tags`.
+
+### Lexer / parser
+
+- Two-pass lexer (block pass, then inline pass per block); syntax-specific
+  `VimwikiToken`s with byte-offset spans, collected eagerly into a
+  `TokenStream`.
+- Hand-rolled recursive-descent parser (not a combinator library). Resilient:
+  malformed input yields an `ErrorNode` and parsing continues — a document
+  never fails to parse.
+- Full re-parse on every `didOpen` / `didChange` (no incremental parsing).
+
+### Syntax plugin interface
+
+Syntaxes register against a `SyntaxRegistry` keyed by id and file extension:
+
+```
+SyntaxPlugin { id, display_name, file_extensions, lexer, parser }
+```
+
+vimwiki (`.wiki`) is the only registered syntax; the registry exists so a
+markdown plugin can be added without touching the LSP or editor layers.
+
+### Renderer
+
+`Renderer` trait writes to a `dyn Write`; `HtmlRenderer` is the implementation.
+Link resolution is injected as a callback. Template substitution supports
+`{{title}}`, `{{content}}`, `{{date}}`, `{{root_path}}`, `{{toc}}`, `{{css}}`.
+`color_dic` maps colour-tag names to CSS values, falling back to
+`class="color-<name>"`.
+
+---
+
+## 3. LSP server
+
+### Advertised capabilities
+
+| Capability | Notes |
+|---|---|
+| `textDocumentSync` | full sync (open/close/change/save) |
+| `semanticTokensProvider` | full + range; custom vimwiki token legend |
+| `documentSymbolProvider` / `workspaceSymbolProvider` | outline + workspace search (tags included) |
+| `definitionProvider` / `referencesProvider` | link follow + backlinks |
+| `hoverProvider` | link preview |
+| `completionProvider` | trigger `[` |
+| `renameProvider` | cross-document link rewrite |
+| `foldingRangeProvider` | heading blocks + top-level lists |
+| `executeCommandProvider` | see command surface below |
+| `workspace.fileOperations` | `did_rename` + `did_delete` for `**/*.wiki`, `**/*.md` |
+| `positionEncoding` | UTF-8 when client supports LSP 3.17+, else UTF-16 |
+
+Workspace indexing runs as a background tokio task reporting via
+`window/workDoneProgress`; nav features answer with partial data until the
+scan completes. The document store is an `Arc<DashMap<Url, DocumentState>>`
+holding text + AST + version.
+
+### executeCommand surface
+
+All editing commands return a `WorkspaceEdit` (applied via
+`workspace/applyEdit`) built through `edits::WorkspaceEditBuilder`, so the AST
+stays the source of truth. Navigation commands return a `Location`.
+
+| Namespace | Commands |
+|---|---|
+| `list` | `toggleCheckbox` `cycleCheckbox` `rejectCheckbox` `nextTask` `removeDone` `renumber` `changeSymbol` `changeLevel` |
+| `table` | `insert` `align` `moveColumn` |
+| `heading` | `addLevel` `removeLevel` |
+| `link` | `pasteWikilink` `pasteUrl` |
+| `toc` / `links` | `toc.generate` · `links.generate` |
+| `workspace` | `checkLinks` `findOrphans` |
+| `diary` | `openToday` `openYesterday` `openTomorrow` `openIndex` `generateIndex` `next` `prev` `listEntries` `openForDate` |
+| `tags` | `search` `generateLinks` `rebuild` |
+| `export` | `currentToHtml` `allToHtml` `allToHtmlForce` `browse` `rss` |
+| `wiki` | `listAll` `select` `openIndex` `tabOpenIndex` `gotoPage` |
+| `file` | `delete` |
+
+`workspace/rename` emits a `RenameFile` op plus `[[A]]` → `[[B]]` rewrites
+across every linking page (anchors and descriptions preserved). Closed
+documents are re-parsed on demand so cross-document edits use current source.
+
+### Diagnostics
+
+Composable collector chains parse errors (`ErrorNode` walk) and broken-link
+checks (wiki target / anchor / `file:` / `local:` existence). Per-source
+severity is config-driven (`diagnostic.link_severity`: `off|hint|warn|error`);
+raw and external URLs are never diagnosed.
+
+---
+
+## 4. Editor integration
+
+### Installation
+
+Pre-built binaries are published as Gitea release assets
+(`nuwiki-ls-{version}-{target}.tar.gz`) and fetched at install time by
+`lua/nuwiki/install.lua` (Neovim) or `scripts/download_bin.vim` (Vim build
+hooks), installed to `{plugin_dir}/bin/nuwiki-ls`. Falls back to
+`cargo build --release` when download fails or
+`g:nuwiki_build_from_source = 1`.
+
+`plugin/nuwiki.vim` dispatches: Neovim → `require('nuwiki').setup()`; Vim →
+`nuwiki#lsp#start()` (prefers `vim-lsp`, falls back to `coc.nvim`). On Neovim
+the server is registered via `vim.lsp.config{}` + `vim.lsp.enable`, with a
+`vim.lsp.start` autocmd fallback.
+
+### Configuration
+
+Single-wiki (v1.0) and multi-wiki forms both work; the scalar form desugars to
+a one-entry `wikis` list.
+
+```lua
+require('nuwiki').setup({
+  -- single-wiki shorthand
+  wiki_root = '~/vimwiki', file_extension = '.wiki', syntax = 'vimwiki',
+  log_level = 'warn',
+
+  -- or multi-wiki
+  wikis = {
+    { name = 'personal', root = '~/vimwiki', diary_rel_path = 'diary',
+      diary_frequency = 'daily', html = { html_path = '~/vimwiki/_html' } },
+  },
+
+  diagnostic = { link_severity = 'warn' },
+  mappings = {                  -- all default true except mouse
+    enabled = true, wiki_prefix = true, links = true, lists = true,
+    headers = true, table_editing = true, diary = true, html_export = true,
+    text_objects = true, mouse = false,
+  },
+  folding = 'lsp',              -- lsp | expr | off
+})
+```
+
+Per-wiki keys include `index`, `diary_rel_path`/`diary_index`/
+`diary_frequency`/`diary_start_week_day`/`diary_sort`/`diary_caption_level`/
+`diary_header`, `listsyms`/`listsyms_propagate`/`list_margin`,
+`links_space_char`, `nested_syntaxes`, `auto_toc`, `maxhi`, and an `html`
+table (`html_path`, `template_path`/`template_default`/`template_ext`/
+`template_date_format`, `css_name`, `auto_export`,
+`html_filename_parameterization`, `exclude_files`, `color_dic`).
+
+### Command surface
+
+`ftplugin/vimwiki.vim` (Vim) and `lua/nuwiki/commands.lua` (Neovim) define the
+vimwiki command set with `:Vimwiki*` names plus `:Nuwiki*` aliases — index/tab
+index/UI select, diary (note/yesterday/tomorrow/next/prev/index/generate),
+link follow/backlinks/next/prev, goto/delete/rename, list toggle/reject/
+remove-done, TOC, generate/check links, find orphans, tags rebuild/search/
+generate, HTML 2HTML/browse/all/rss, table insert/move/colorize, and paste
+link/url. Search uses `lvimgrep` and backlinks/follow use built-in LSP
+requests; the rest route to `executeCommand`.
+
+### Default keymaps
+
+Buffer-local, gated per subgroup by `mappings.*`:
+
+- **Wiki** `<Leader>ww`/`wt`/`ws`/`wi`, `<Leader>w<Leader>w|y|t|m|i`,
+  `<Leader>wn`/`wd`/`wr`/`wc`
+- **Links** `<CR>` (follow / wrap-word), `<S-CR>`/`<C-CR>`/`<C-S-CR>`
+  (split/vsplit/tab), `<BS>` (back), `<Tab>`/`<S-Tab>` (next/prev link), `+`
+  (wrap as wikilink)
+- **Lists** `<C-Space>` (toggle), `gnt` (next task), `gln`/`glp` (cycle
+  forward/back), `glx` (reject), `gll`/`glh` + `gLl`/`gLh` (indent/dedent,
+  item vs subtree), `glr`/`gLr` (renumber list/all), `gl<Space>`/`gL<Space>`
+  (remove done, list/whole-doc), `o`/`O` (open with bullet); insert-mode
+  `<C-T>`/`<C-D>`, `<C-L><C-J>`/`<C-L><C-K>`, `<C-L><C-M>`; smart `<CR>`/`<Tab>`
+- **Headers** `=`/`-` (deeper/shallower), `]]`/`[[` (next/prev), `]=`/`[=`
+  (sibling), `]u`/`[u` (parent) — pure VimL/Lua, no LSP round-trip
+- **Tables** `gqq`/`gww` (align), `<A-Left>`/`<A-Right>` (move column)
+- **Diary** `<C-Down>`/`<C-Up>` (next/prev entry)
+- **HTML** `<Leader>wh`/`whh`/`wha` (export/browse/all)
+- **Mouse** (opt-in) `<2-LeftMouse>` follow + shift/ctrl variants
+
+**Text objects:** `ah`/`ih` (heading section), `aH`/`iH` (heading + subtree),
+`al`/`il` (list item), `a\`/`i\` (table cell), `ac`/`ic` (table column). Pure
+VimL/Lua.
+
+### Folding
+
+Primary: LSP `textDocument/foldingRange` (`folding::folding_ranges`, heading
+blocks + top-level lists). Fallback: a pure Lua `foldexpr` in
+`lua/nuwiki/folding.lua` for clients without `foldingRange`.
+
+### Health check
+
+`:checkhealth nuwiki` verifies the binary exists and responds to `--version`,
+the LSP client is attached, `.wiki` filetype detection works, and reports
+registered commands and per-wiki index state.
+
+---
+
+## 5. Vimwiki syntax support
+
+Parsed and highlighted (custom semantic-token legend; `syntax/nuwiki.vim`
+provides a no-LSP fallback):
+
+- **Typefaces** bold `*…*`, italic `_…_`, bold-italic, strikethrough `~~…~~`,
+  inline code, super `^…^` / sub `,,…,,`, keywords (TODO/DONE/STARTED/FIXME/
+  FIXED/XXX/STOPPED)
+- **Links** plain/described/subdir/root/absolute wikilinks, `[[dir/]]`,
+  interwiki (`wiki1:` / `wn.Name:`), diary, anchor-only and `Page#anchor`,
+  raw URLs, `file:`/`local:`, transclusion `{{url|alt|attrs}}`
+- **Headers** levels 1–6, centered
+- **Lists** unordered (`-` `*` `#`), ordered (`1.` `1)` `a)` `A)` `i)` `I)`),
+  nested/mixed, multi-line items, definition lists, all six checkbox states
+- **Tables** `|`-delimited, header separator, column alignment markers,
+  colspan `>` / rowspan `\/`, inline formatting in cells
+- **Blocks** preformatted `{{{ … }}}` (optional language), inline math `$…$`,
+  block math `{{$ … }}$` (optional environment), blockquotes, comments
+  (`%% …`), horizontal rule `----`
+- **Tags** `:tag1:tag2:` (file / heading / standalone scope), tag-as-anchor
+- **Placeholders** `%title` `%nohtml` `%template` `%date`
+
+---
+
+## 6. CI/CD
+
+`.gitea/workflows/ci.yaml` runs on every push and PR:
+
+| Job | Command |
+|---|---|
+| fmt | `cargo fmt --all -- --check` |
+| clippy | `cargo clippy --workspace --all-targets -- -D warnings` |
+| test | `cargo test --workspace --all-targets` |
+| keymaps | `development/tests/test-keymaps.sh` (Neovim 0.11) + `test-keymaps-vim.sh` (Vim) |
+
+`.gitea/workflows/release.yaml` triggers on `v*` tags: cross-compiles the four
+Linux targets (gnu/musl × x86_64/aarch64) via `cross`, packages `.tar.gz`, and
+creates a Gitea release using `RELEASE_TOKEN`. macOS and Windows binaries are
+built manually and attached to the same release. crates.io publishing is not
+wired up.
+
+A change is semver-breaking if it alters `nuwiki-core` AST nodes, the
+`SyntaxPlugin`/`Renderer` traits, the user-config schema, or removes an LSP
+capability.