docs: explain custom web rule facts

concepts/analyzers/typescript-sveltekit.mdx

@@ -105,8 +105,71 @@ also reads literal SvelteKit `kit.alias` values. When a required alias is dynami
 Fensu fails with a configuration diagnostic rather than guessing. A missing
 generated `.svelte-kit/tsconfig.json` is accepted on a fresh checkout.
 
-Python custom rules and `fensu map` remain Python analyzer features. Web targets
-use the shipped native `typescript` or `sveltekit` catalogue.
+## Custom web rules
+
+Python-authored custom rules can extend a TypeScript or Svelte target without
+changing its CLI, configuration, selectors, or policy model. Declare analyzer
+applicability on the normal `@rule` decorator:
+
+```python
+from fensu import AnalyzerId, Family, Fault, File, RuleContext, rule
+
+
+@rule(
+    code="XWEB001",
+    family=Family.CUSTOM,
+    slug="resolved-import-boundary",
+    message="Import crosses the configured boundary",
+    analyzers=(AnalyzerId.TYPESCRIPT,),
+    cacheable=True,
+)
+def resolved_import_boundary(*, file: File, ctx: RuleContext) -> list[Fault]:
+    facts = ctx.web.file(file)
+    if facts is None:
+        return []
+    return [
+        ctx.fault_at(location=edge.location)
+        for edge in ctx.graph.imports(file)
+        if edge.target is not None and edge.target.role == "_state"
+    ]
+```
+
+Configure it like any other custom rule:
+
+```toml
+[targets.web]
+analyzer = "typescript"
+roots = ["src"]
+tests = ["tests"]
+tooling = []
+rule_paths = ["rules/web.py"]
+select = ["FPTS", "XWEB001"]
+```
+
+`ctx.web` exposes immutable Fensu-owned facts for TypeScript, JavaScript, and
+Svelte sources. These include source kinds, resolved import targets, functions,
+classes, models, bindings, calls, resources, exports, source locations, and stable
+text handles. `ctx.graph` exposes the same resolved imports through the common
+architecture graph, including `tsconfig.json`, `jsconfig.json`, `$lib`, and
+literal SvelteKit alias resolution.
+
+Svelte files add `SvelteFileFacts` for component markup, route identity, script
+contexts, and runes. Svelte state modules such as `session.svelte.ts` are marked
+separately and expose only recognized top-level initializer runes; nested calls
+are not promoted to module-owned state.
+
+File rules run once per selected source. A typed `Project` callback runs once for
+the target and can query `ctx.web.files` and `ctx.project.tree`. Use focused
+`ctx.web.file(...)`, tree, or graph queries when unrelated edits should preserve a
+cached result. Every query records its actual answer for cache replay.
+
+Web parsing and built-in rules always remain native and Node-free. Fensu starts a
+bounded Python host only when configured custom sources and an active `X` selector
+require hosted resolution. Native-only, unselected, and custom selections whose
+selector prefixes are wholly covered by ignore prefixes remain Python-free. Actual
+rule applicability is resolved inside the host. Custom diagnostics then pass
+through the normal warnings, ignores, exceptions, rendering, and exit-code
+handling. `fensu map` remains a Python analyzer feature.
 
 ## Gradual adoption
 

reference/rule-context.mdx

@@ -100,9 +100,11 @@ unsupported path objects. `FilePosition` includes `path`, `analyzer`, `source_ki
 
 ## `ctx.graph`
 
-For Python targets, an immutable architecture graph resolved from static imports
-and authoritative discovered modules. Unresolved imports remain explicit and
-dynamic imports are not represented.
+For Python, TypeScript, and Svelte targets, an immutable architecture graph
+resolved from static imports and authoritative discovered modules. Unresolved
+imports remain explicit and dynamic imports are not represented. Web graph
+resolution reuses the native analyzer's static TypeScript, JavaScript, SvelteKit,
+and configured alias resolution.
 
 | Call | Returns | Purpose |
 | --- | --- | --- |
@@ -139,6 +141,38 @@ Each broad or focused call records its answer for subject-aware cache replay. Us
 focused `file()` or `crate()` lookup when unrelated source or Cargo changes should
 not invalidate a cached result.
 
+## `ctx.web`
+
+For TypeScript and Svelte targets, a versioned immutable fact view transferred from
+the native analyzers. It contains no parser-library nodes and does not require
+Node.
+
+| Call | Returns | Purpose |
+| --- | --- | --- |
+| `files` | `tuple[WebFileFacts, ...]` | All discovered direct, support, excluded, and generated web source facts. |
+| `file(file_or_path)` | `WebFileFacts \| None` | One focused file lookup by `File` or `ProjectPath`. |
+
+`WebFileFacts` exposes its analyzer, `WebSourceKind`, `WebSourcePurpose`, module,
+source root, scope, authored source, optional parse error, and immutable imports,
+functions, classes, models, bindings, calls, resources, re-exports, and export
+counts. `WebImportFact.target` is a `File` only when the native analyzer proves a
+project-local destination. Use `ctx.graph` for resolved dependency and dependent
+queries.
+
+`syntax_handles` contains stable Fensu-owned `WebSyntaxHandle` byte ranges for
+imports, declarations, calls, resources, re-exports, Svelte scripts, and runes.
+Pass one to `WebFileFacts.text(handle)` to retrieve its authored text without
+receiving an analyzer AST.
+
+On Svelte targets, `WebFileFacts.svelte` is a `SvelteFileFacts` extension when the
+file is a component or state module. It records script contexts, recognized
+top-level runes, component markup, route identity, and state-module identity.
+TypeScript-only targets do not require this extension.
+
+Broad `files` and focused `file()` calls record their exact answers for
+subject-aware cache replay. Tree and graph calls made during the same invocation
+record their own query-specific dependencies.
+
 ## `ctx.text`, `ctx.syntax`, `ctx.relations`
 
 Source text, opaque syntax identities, and syntax relationships for the current
@@ -160,9 +194,11 @@ The zone protocols are `FactAnalysis`, `ProjectAnalysis`, `TextAnalysis`,
 `SyntaxAnalysis`, and `RelationAnalysis`, all exported from `fensu`.
 
 The table above describes the Python analysis zones. Serialized Rust rules use
-`ctx.rust`, `ctx.project.tree`, `ctx.source`, and stable locations. `ctx.graph`,
-`ctx.syntax`, and `ctx.relations` are unavailable because parser implementation
-objects are not part of the Rust authoring contract.
+`ctx.rust`, `ctx.project.tree`, `ctx.source`, and stable locations. Serialized web
+rules use `ctx.web`, `ctx.graph`, `ctx.project.tree`, `ctx.source`, and
+`WebSyntaxHandle`. The generic `ctx.syntax` and `ctx.relations` zones are
+unavailable because parser implementation objects are not part of native-analyzer
+authoring contracts.
 
 ## Fault construction
 
@@ -328,6 +364,24 @@ are frozen dataclasses; inspect exact fields with your editor's type information
 | `RustItemFact` | Function, struct, enum, trait, implementation or module declaration. |
 | `RustUseFact` | Authored `use` path and explicit resolution evidence. |
 
+**Web facts**
+
+| Model | Describes |
+| --- | --- |
+| `WebWorkspaceFacts` | Versioned TypeScript or Svelte target facts. |
+| `WebFileFacts` | One discovered web source, its semantic facts, source, and parse result. |
+| `WebImportFact` | Authored import bindings, flags, location, and optional resolved target. |
+| `WebFunctionFact` | Function ownership, annotations, return type, and structural metrics. |
+| `WebClassFact` | Class identity, export status, and error-class classification. |
+| `WebModelFact` | Interface or type-literal model shape and readonly evidence. |
+| `WebBindingFact` | Top-level binding and optional initializer call. |
+| `WebCallFact` | Named call, lexical function owner, ancestors, and cleanup evidence. |
+| `WebResourceFact` | Statically recognized resource family, binding, and call ancestry. |
+| `WebSyntaxHandle` | Fensu-owned kind, name, location, and stable source byte range. |
+| `SvelteFileFacts` | Component, route, state-module, script, and rune extensions. |
+| `SvelteScriptFact` | One module or instance script block. |
+| `SvelteRuneFact` | One recognized module-owned rune and source location. |
+
 **Test facts**
 
 | Model | Describes |