docs: de-duplicate run instructions, READMEs track current code

diigo-dump/README was stale three ways: described the pre-DO connect
flow (askpass + DIIGO_COOKIE, both retired), referenced deleted files
(src/webapp.ts), and named the old entrypoint. Rewritten against
current code (DiigoBridge, DO storage state surface, state-aware
/_connect); run/connect/deploy instructions now live only in the
capsite checklist, linked (intra-repo docs link rather than repeat).
webapp/README Run section: port note corrected (two-config run makes
diigo-dump the primary) and pointed at the checklist as the source.

Generated-by: opencode (GLM)

webapp/README.md

@@ -23,7 +23,9 @@ grows past a form or two.
 
 ## Run
 
-    npx wrangler dev   # → http://localhost:8788 (its own wrangler dir)
+    npx wrangler dev   # → its own ready line (usually :8787 with the
+                       # two-config diigo-dump run; standalone, :8788)
 
 Status: typechecks; mint + drive not yet exercised end-to-end (needs the
-combined dev run; see ../diigo-dump/README.md).
+combined dev run; see ../capsite-checklist.md — it is the single
+source for run/connect/deploy instructions).