feat: tsconfig compilerOptions.paths — aliased bare specifiers join the graph and follow moves

- index/tsconfig: JSONC sanitize (comments, trailing commas), baseUrl +
  star/exact path keys, first candidate only, longest-prefix wins; invalid
  or missing tsconfig silently means no aliases
- resolution pass: '.'-prefixed specifiers resolve relatively as before,
  bare ones go through the alias table and join the importer graph
- planner: remap keeps the alias shape while the moved file stays inside
  the mapped tree (morphological, since destinations do not exist yet),
  exact keys keep meaning only while still resolving to the target;
  otherwise the previous relative rewrite applies unchanged
- resolve_base extracted from resolve_module (shared extension/index
  guessing); MODULE_EXTS is the exact inverse for remapping
- e2e: @utils/str.ts -> @utils/text.ts inside alias, -> ./core/text.ts
  when leaving it, @cfg falls back to ./settings; check passes on aliases

docs/SKILL.md

@@ -40,6 +40,13 @@ working tree unstaged either way — stage or commit them yourself.
 `--json` reports the choice as `moved_via` (`"git"`/`"fs"`) and, on a
 dry-run, `would_move_via`.
 
+tsconfig `paths`: `compilerOptions.paths` prefixes (`@/*`, `@cfg` exact
+keys, `baseUrl`-relative) map bare specifiers into the project graph, so
+aliased imports participate in `mv` — the rewrite keeps the alias shape
+while the new file stays inside the mapped tree and falls back to a
+relative specifier otherwise. `extends` chains and 2nd+ candidate lists
+are not followed (v1); an invalid tsconfig silently means "no aliases".
+
 ### check — find broken imports and Java layout errors
 
 ```