AutomationBridge: registry-driven verbs to end the seven-way merge-conflict hotspot

Problem

Nearly every bridge-touching PR in the 2026-07 cycle (#4100, #4102, #4116, #4121, #4122, #4124, #4131, #4137) conflicted in the same seven places, because the bridge uses centralized, ordered lists that every verb must append to:

1. The verb banner string in AutomationServer::start() — also drifted three times this cycle (verbs missing from the banner had to be re-added in three separate PRs).
2. handleLine's positional-parse if/else chain — every verb adds an else if arm at the same insertion point.
3. The dispatch if-chain — same shape, same function.
4. doGet's model chain + the "unknown model" error string that enumerates all models (rhi vs flags vs tracedebug collided repeatedly).
5. tools/automation_probe.py: the argparse choices=[…] list, the rest help mega-string, and the elif chain — the worst offender, including silent bad merges (duplicate pan subcommand blocks after #4124's rebase; a value-vs-target wire-contract drift in #4116).
6. docs/automation-bridge.md: the verb summary table + adjacent ### sections (two ### rightClick sections silently survived a merge in #4137).
7. The .h handler-member/setter cluster + main.cpp wiring lines for stateful verbs.

Root cause: N verbs × M concurrent PRs all appending to shared lists in fixed order. Hand-maintained "list of all X" strings are simultaneously a conflict magnet and a drift-bug source.

Design

Phase 1 — verb registry spine (no behavior change):

• A VerbSpec table: {name, aliases, argShape (enum or parse lambda), requiredFields, txGated, help, handler}. handleLine becomes: look up verb → apply its arg shape → validate required fields → dispatch. Every existing doVerb body survives untouched.
• Derive every enumeration: the startup banner = join(registry.names()); unknown command / unknown model / unknown slice action error strings generated from the tables. Deletes the drift class and the conflict class in one move.
• doGet gets the same treatment: model name → snapshot lambda map.
• A read-only verbs introspection verb that dumps the registry (name, arg shape, help) for tooling.

Phase 2 — generic probe:

• automation_probe.py drops choices, the help mega-string, and most of the elif chain: a generic probe <verb> [args…] passthrough plus a small mapping table for the few verbs needing custom arg handling (get, grab, clickAt). Optionally validates against the live verbs dump. Structurally ends "probe drifted from server."

Phase 3 — follow-ups:

• Split verb registrations into family TUs (AutomationVerbs_Slice.cpp, AutomationVerbs_Layout.cpp, …) so a new verb is a new file — the same decomposition medicine docs/architecture/mainwindow-decomposition.md prescribes for MainWindow, for the same multi-agent-contributor reason.
• tools/gen_bridge_docs.py --check: regenerate the docs summary table from the registry, fail CI on drift; plus a duplicate-heading lint for the silent-merge-dup class.
• Consider GitHub merge queue: five armed PRs serially invalidated each other this cycle; a queue rebases+tests each automatically.

Phases 1–2 are one mechanical PR (in progress). — filed with Claude Code on behalf of KK7GWY

Start with AutomationServer::start(), handleLine, and doGet to map the current verb and model chains, then inspect tools/automation_probe.py and docs/automation-bridge.md. Phase 1–2 is done when registry-derived enumerations and generic probing replace the duplicated lists without behavior changes, including the verbs introspection output.