fix(resolution): calls through an imported singleton resolve to the method (#1315)

reproStore.notifyJoinGuildStatus() after `import { reproStore }`
resolved its calls edge to the exported CONSTANT (resolvedBy:'import'),
while the identical same-file call resolved to the method via
local-variable receiver inference (#1108) — so `callers <method>`
missed every cross-file use and a widely-used method could look
unused (#1292).

resolveViaImport's member-descend now handles imported VALUES alongside
the #825 static-member case: when the base resolves to a
constant/variable, the value's type is inferred from ITS OWN
declaration lines in the exporting file (the shared #1108 pattern
table: `= new T(...)` initializers and type annotations) and the member
is resolved AND VALIDATED on that type via resolveMethodOnType. A
failed inference or validation keeps the existing constant edge —
never a fabricated one. Calls only; plain member reads still reference
the value.

excalidraw control: byte-identical graph (10,653 nodes / 19,483 calls
edges before and after).

Fixes #1292

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -18,6 +18,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### Fixes
 
+- TypeScript/JavaScript method calls through an imported singleton (`import { store } from './store'; store.notify()`) now resolve to the class method instead of the exported constant, so `codegraph callers` sees cross-file callers of the method — previously only same-file calls were attributed and a method used everywhere could look unused. The same declaration-based type inference applies across the languages that share it (Python, Java, Kotlin, Go, and more), and a failed inference keeps the old edge rather than guessing. (#1292)
 - `codegraph node <symbol> -f <file>` now prints the symbol's source body. Pinning an ambiguous name to a specific file (the whole point of `-f` when many files define the same function) returned only the location and caller trail with no code. (#1284)
 - Deleting a whole directory is now picked up by watch mode: the files inside it are removed from the index on the next auto-sync instead of lingering as stale records until an unrelated edit happened to trigger one. Operating systems often report a directory deletion as a single event on the directory itself (with no per-file events for its contents), which the watcher previously discarded. (#1285)
 - `codegraph sync` now gets the same slow-disk fix that made full indexing fast in 1.4.0: database checkpointing is deferred for the whole incremental run instead of firing every few megabytes of writes. On mechanical drives and other high-latency storage, a small sync on a large index no longer stalls for minutes at near-zero CPU — the cost of a sync scales with what changed, not with the size of the existing index. The same `CODEGRAPH_NO_WAL_DEFER=1` switch turns it off. (#1248)