feat(ocaml): add OCaml .ml/.mli extractor (optional tree-sitter-ocaml extra)

New graphify/extractors/ocaml.py handles both the implementation grammar
(language_ocaml, .ml) and the interface grammar (language_ocaml_interface,
.mli). Emits nodes for modules, top-level/module-level values and functions,
types and their variant constructors; edges for defines/contains, open ->
imports_from, and application -> calls. Qualified paths (Geo.area) resolve to
the final value name, not the module qualifier; local let ... in bindings do
not mint nodes or steal call attribution. Cross-file open/call targets are
sourceless stubs so the corpus rewire collapses them onto the unique real
definition (no #1402 sourced-stub leak).

Wired into detect.py (CODE_EXTENSIONS), extract.py (dispatch +
_EXTRA_FOR_EXTENSION), pyproject.toml ([ocaml] extra + all + dev dep), and
README. Adds tests/test_ocaml.py (behind importorskip).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -266,6 +266,7 @@ Codex users also need `multi_agent = true` under `[features]` in `~/.codex/confi
 | `dm` | BYOND DreamMaker `.dm`/`.dme` AST extraction (may need a C compiler + `python3-dev` if no wheel matches your platform) | `uv tool install "graphifyy[dm]"` |
 | `terraform` | Terraform / HCL `.tf`/`.tfvars`/`.hcl` AST extraction | `uv tool install "graphifyy[terraform]"` |
 | `pascal` | Pascal / Delphi `.pas`/`.dpr`/`.dpk`/`.inc` AST extraction (more accurate `calls`/`inherits` edges; falls back to a regex extractor when absent) | `uv tool install "graphifyy[pascal]"` |
+| `ocaml` | OCaml `.ml`/`.mli` AST extraction | `uv tool install "graphifyy[ocaml]"` |
 | `chinese` | Chinese query segmentation (jieba) | `uv tool install "graphifyy[chinese]"` |
 | `all` | Everything above | `uv tool install "graphifyy[all]"` |
 
@@ -335,9 +336,10 @@ To remove graphify from all platforms at once: `graphify uninstall` (add `--purg
 
 | Type | Extensions |
 |------|-----------|
-| Code (36 tree-sitter grammars) | `.py .ts .mts .cts .js .jsx .tsx .mjs .go .rs .java .c .cpp .cc .cxx .h .hpp .cu .cuh .metal .rb .cs .kt .kts .scala .php .swift .lua .luau .toc .zig .ps1 .psm1 .psd1 .ex .exs .m .mm .jl .vue .svelte .astro .groovy .gradle .dart .v .sv .svh .sql .f .f90 .f95 .f03 .f08 .pas .pp .dpr .dpk .lpr .inc .dfm .lfm .lpk .sh .bash .json .dm .dme .dmi .dmm .dmf .sln .slnx .csproj .fsproj .vbproj .xaml .razor .cshtml` (`.dm`/`.dme` requires `uv tool install graphifyy[dm]`; `.mts`/`.cts` reuse the TypeScript grammar, `.cc`/`.cxx` and CUDA `.cu`/`.cuh` and Metal `.metal` reuse the C++ grammar) |
+| Code (37 tree-sitter grammars) | `.py .ts .mts .cts .js .jsx .tsx .mjs .go .rs .java .c .cpp .cc .cxx .h .hpp .cu .cuh .metal .rb .cs .kt .kts .scala .php .swift .lua .luau .toc .zig .ps1 .psm1 .psd1 .ex .exs .m .mm .ml .mli .jl .vue .svelte .astro .groovy .gradle .dart .v .sv .svh .sql .f .f90 .f95 .f03 .f08 .pas .pp .dpr .dpk .lpr .inc .dfm .lfm .lpk .sh .bash .json .dm .dme .dmi .dmm .dmf .sln .slnx .csproj .fsproj .vbproj .xaml .razor .cshtml` (`.dm`/`.dme` requires `uv tool install graphifyy[dm]`, `.ml`/`.mli` requires `uv tool install graphifyy[ocaml]`; `.mts`/`.cts` reuse the TypeScript grammar, `.cc`/`.cxx` and CUDA `.cu`/`.cuh` and Metal `.metal` reuse the C++ grammar) |
 | Salesforce Apex | `.cls .trigger` (regex-based; classes, interfaces, enums, methods, triggers, SOQL/DML edges) |
 | Terraform / HCL | `.tf .tfvars .hcl` (requires `uv tool install graphifyy[terraform]`) |
+| OCaml | `.ml .mli` (requires `uv tool install graphifyy[ocaml]`) |
 | MCP configs | `.mcp.json` `mcp.json` `mcp_servers.json` `claude_desktop_config.json` — extracts server nodes, package refs, env var requirements |
 | Package manifests | `apm.yml` `pyproject.toml` `go.mod` `pom.xml` — one canonical package node per package (by name) plus `depends_on` edges, so a package referenced from many manifests is a single hub |
 | Docs | `.md .mdx .qmd .html .txt .rst .yaml .yml` (markdown `[text](./other.md)` links and `[[wikilinks]]` become `references` edges between docs) |