fix(ui): show synthesis as a 'Linking dynamic dispatch' phase; mute node:sqlite warning spam (#1299)

Two first-run UX bugs surfaced by indexing a real 1,342-file C repo:

1. After 'Resolving refs' hit 100%, the ~40 dynamic-dispatch synthesis
   passes ran with no progress surface, so the bar sat frozen at 100%
   long enough to read as a hang (the C fn-pointer pass alone can hold
   for a while on C-heavy repos). Synthesis now reports per-pass
   progress through a new 'linking' IndexProgress phase, rendered as
   'Linking dynamic dispatch'. The step total is pinned by a test to
   the synthesizer's actual __mark() count so adding a pass without
   bumping it fails loudly.

2. node:sqlite's ExperimentalWarning is emitted once per THREAD, so the
   main process plus every parse worker printed it mid-index,
   interleaved with the progress UI. All launch paths now pass
   --disable-warning=ExperimentalWarning: both bundle launchers, the
   Windows npm-shim invocation, and the CLI self-relaunch
   (NODE_RUNTIME_FLAGS, deliberately excluded from the re-exec gate so
   an older installed launcher never triggers a pointless re-exec, and
   version-gated off nodes older than the flag).

Verified end-to-end on the same repo: zero warnings, live linking bar,
byte-identical graph (50,520 nodes / 148,232 edges). Full suite green.

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

scripts/npm-shim.js

@@ -98,8 +98,12 @@ function launcherIn(dir) {
 // --liftoff-only keeps tree-sitter's WASM grammars off V8's turboshaft tier to
 // avoid the Zone OOM on Node >= 22 (issues #293/#298). The unix bin/codegraph
 // launcher already passes it; on Windows we invoke node.exe directly so add it.
+// --disable-warning=ExperimentalWarning mutes node:sqlite's per-thread
+// "experimental feature" warning, which otherwise prints once per parse worker
+// mid-index, shredding the progress UI. The bundled node.exe is always new
+// enough for both flags.
 function liftoff(entry) {
-  return ['--liftoff-only', entry].concat(process.argv.slice(2));
+  return ['--liftoff-only', '--disable-warning=ExperimentalWarning', entry].concat(process.argv.slice(2));
 }
 
 // Download + cache the platform bundle from GitHub Releases. Returns