/flow says in one sentence what is clogging the lane, and names a failing test shared by three pulls #11454

Intent: the owner sees why pulls are not landing without opening each one.

Done:

• [ ] /flow shows clogSays (src/flow/clog_words.ts) as the bottleneck line, fed by the facts the flow page already reads
• [ ] a test failing on 3+ open pulls is shown once by sharedRed (src/flow/shared_red.ts), with the pulls it holds, linked
• [ ] pairs of open pulls that touch the same files are listed by conflictPairs (src/flow/conflict_pairs.ts), at most 20, linked to both pulls
• [ ] each of the three has a test on the page's HTML; no new red banner (design-lint clean); before/after looks, light and dark

Done means reachable: the module leaves scripts/unreached-allow.json in the same pull (test/unreached.test.ts goes red on an entry that is no longer unreached), the page is reachable from /flow in two taps, and a test fails without the wiring. Read the module and src/web/pages/flow.ts first; if main already calls it, say so in the pull with the commit. Add the section as its own small builder file and mount it with one line, so pulls on the other flow modules do not collide.

Files: src/flow/clog_words.ts, shared_red.ts, conflict_pairs.ts, a new src/web/pages/flow-clog.ts, src/web/pages/flow.ts (one mount line), scripts/unreached-allow.json, docs/features/flow-clog.md, tests. Risks: pulls reading file lists per request is slow; read them from what /flow already loads and keep the page under its budget. Suggested brief: scout.