feat(temporal): resolve activity/workflow dispatch names from env-var-with-default vars

[avfirsov]

Summary

Resolve a Temporal activity / workflow dispatch name when it comes from a local variable read from an env var with a literal default, instead of leaving the call unresolved — landing the resolved edge at the speculative tier since the runtime env value may differ from the default.

This is one half of a split from #75 (the other half — Go-side query/signal/update handler edges — is in a separate PR so each can be reviewed independently).

Changes

• When an ExecuteActivity / ExecuteLocalActivity / ExecuteChildWorkflow name argument is a bare identifier assigned, in the enclosing function, from an env-var-with-literal-default, resolve the dispatch to that literal default:

  actName := cmp.Or(os.Getenv("CHARGE_ACTIVITY"), "ChargeCard")
  workflow.ExecuteActivity(ctx, actName, id)   // → activity "ChargeCard"
  
  name := os.Getenv("K"); if name == "" { name = "ChargeCard" }

• The lookup is narrow and intra-procedural, anchored on a literal os.Getenv / os.LookupEnv read (so the value is provably env-sourced — this is not general constant propagation), and only considers assignments lexically before the call. Anything else is left unresolved, no guessing.
• The parser tags the stub edge temporal_name_origin=env_default; the resolver then lands it at the speculative tier (OriginSpeculative, confidence 0.4, MetaSpeculative=true) rather than ast_resolved. The edge is present but hidden from default queries, reusing the existing speculative-edge convention (OriginSpeculative / MetaSpeculative, cf. speculative_dispatch.go).

Testing

• All tests pass (go test -race ./...) for the touched packages (internal/parser/languages, internal/resolver, internal/indexer). The only failures in my environment are the pre-existing internal/indexer watcher tests failing with inotify ... too many open files (a local WSL fd-limit issue, unrelated — no watcher files touched).
• New tests added — parser-level (go_temporal_test.go: cmp.Or and if x=="" shapes + negative cases for a plain non-env variable and an env read with no literal default), resolver-level (temporal_calls_test.go: speculative-tier resolution + unresolved-stays-placeholder), and end-to-end (temporal_e2e_test.go).
• Benchmarks — n/a; the lookup is AST-local within the enclosing function and only triggers for a bare-identifier dispatch name.

Checklist

• Code follows existing patterns in the codebase (reuses the OriginSpeculative / MetaSpeculative tier and confidence-label machinery)
• No unnecessary abstractions added
• Language extractor includes Meta["methods"] for interfaces (if applicable) — n/a
• Methods have EdgeMemberOf edges to their containing type (if applicable) — n/a

Notes for reviewers

This is the more opinionated of the two split PRs: it adds a narrow intra-procedural data-flow shortcut, which is a small departure from the otherwise AST-local detector. It's deliberately bounded (literal os.Getenv/os.LookupEnv anchor, literal default only, lexically-before-the-call) and emitted at the speculative/hidden tier precisely so it can't silently distort the high-confidence graph. Happy to gate it behind a flag or narrow it further if you'd prefer.