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>

src/ui/shimmer-progress.ts

@@ -6,6 +6,7 @@ const PHASE_NAMES: Record<string, string> = {
   parsing: 'Parsing code',
   storing: 'Storing data',
   resolving: 'Resolving refs',
+  linking: 'Linking dynamic dispatch',
 };
 
 export interface IndexProgress {