fix(explore): stop NL-question words from hijacking the named-symbol tier when they collide with real callables (#1252)

handleExplore's named-symbol seeding treats every identifier-shaped query
token as "a symbol the agent named" and grants its definition the
named-FIRST sort tier. Natural-language questions broke this assumption:
ordinary words exact-matched unrelated callables ("check" ->
WalCheckpointValve.check, "serve" -> query-worker serve, "initialize" ->
DatabaseConnection.initialize), and those collisions outranked — and within
the per-repo file budget fully displaced — the corroborated answer files,
forcing the agent back to Read/Grep. The >3-def single-pick fallback had
the same hole: on grpc, the #1064 flagship query "add a parameter to
NewClient" itself tiered balancerStateAggregator.add's file to slot #1.

Guard: a shape-precise token (camelCase, PascalCase, snake_case,
qualified) seeds unconditionally — it is an unambiguous symbol reference.
A bare lowercase word seeds only defs whose file another query token
co-names (that token is itself an exact symbol name defined in the same
file — the "check drain fire" sibling-bag shape), which an incidental
English-word collision never is. Applied by filtering cands ahead of both
branches so the overloaded-name fallback is covered too.

Validated per the retrieval playbook: deterministic probes on this repo
(collision queries fixed; sibling-bag and single-camelCase retained), and
baseline-vs-fixed probes on the #1064 repos — Alamofire and excalidraw
byte-identical, grpc improved (the add-collision file drops out and
clientconn.go + dialoptions.go lead). Full suite green.

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

CHANGELOG.md

@@ -11,6 +11,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### Fixes
 
+- `codegraph_explore` no longer lets ordinary English words in a natural-language question hijack the ranking when they happen to match a code symbol's name. A question like "how does the upgrade flow check the latest version" used to treat "check" as a symbol the agent asked for by name, rank that unrelated definition's file first, and crowd the files the question is actually about out of the answer entirely. Precisely written symbol names (camelCase, PascalCase, snake_case, qualified names) still get top billing exactly as before, as do plain-word symbol bags whose words belong together in the same file.
 - PHP method calls made through a class property — `$this->dep->method()`, the dominant call shape in constructor-injection codebases (Symfony, Laravel) — now resolve to the method on the property's declared type, so callers and impact analysis see production call sites instead of reporting a DI-heavy method as uncalled or test-only. Promoted constructor parameters, typed properties, classic constructor assignment (including multi-line signatures), and typed setter injection all count; interface-typed properties resolve to the interface method, and inherited methods resolve through the type hierarchy. Only property-shaped declarations are consulted — a same-named local variable or parameter elsewhere can never mistype the property — and a property whose type can't be recovered statically stays unlinked rather than guessed. Thanks @w0lan. (#1220)
 - `codegraph upgrade` now also refreshes what previous versions installed into your agents — the CodeGraph section in CLAUDE.md / AGENTS.md / GEMINI.md and the MCP entry — so upgrading no longer leaves agents following instructions written for tools that have since been renamed or removed. Refresh-only: agents you never configured are not touched, and your permission and hook choices are preserved. Also available manually as `codegraph install --refresh`, and skippable with `CODEGRAPH_NO_INSTALL_REFRESH=1`. (#1238)
 - `codegraph upgrade` on an npm install now upgrades through npm again instead of quietly creating a second copy that never wins the PATH race — previously `codegraph --version` kept reporting the old version forever, no matter how many times you upgraded. (#1238)