setconfig was acknowledged with unconditional success after
broadcasting Msg::Option, while owning modules reject bad values by
log-and-keep. lightningd persists a setconfig value (configvar_save)
only on a success response, so the blanket ack recorded values clboss
never applied: listconfigs and config.setconfig diverged from the
running configuration, and a non-numeric value persisted for an
int-typed option fails lightningd's own option parse on the next
start -- lightningd refuses to boot.
Add a rejection back-channel to Msg::Option: SetConfigHandler
allocates a shared reject_reason (null on init-time raises, so
aggregate initialization at existing sites is unaffected), the owning
subscriber reports rejection via the new Msg::Option::reject() helper
(a no-op at init time, where quietly keeping the default is right),
and SetConfigHandler -- whose bus.raise() returns only after all
subscribers ran -- fails the command with invalid-params when a
reason was set. All dynamic-option owners in this tree report their
rejections: RebalanceModeManager (unrecognized mode), FundsMover's
three numeric handlers, and AskreneUpdates' shared age/retain
handler.
Introduces the mechanism for runtime-mutable plugin options: an option
marked dynamic can be changed via `lightning-cli setconfig <name> <val>`
without restarting clboss or lightningd. No option opts in yet -- this
is the foundation (the rebalancer mode selector is the first consumer).
- Boss::Msg::ManifestOption gains a bool dynamic field (default false,
preserving the existing startup-only contract).
- Boss::Mod::Manifester emits the per-option dynamic flag in the
getmanifest response, so lightningd knows to forward setconfig for
that option.
- New Boss::Mod::SetConfigHandler module records (name -> dynamic)
from Msg::ManifestOption events, then handles incoming setconfig
CommandRequests: it validates the named option is registered and
dynamic, and re-raises a fresh Msg::Option on the bus, so existing
option handlers re-apply the new value transparently.
Because Msg::Option is now re-emitted at runtime (not only during init),
subscribers must filter by name and tolerate post-init arrival.
AmountSettingsHandler gains an `if (!settings) return` guard: it moves
`settings` away at EndOfOptions, so a later Msg::Option for an unrelated
name must be dropped -- this also fixes a latent assert(settings) crash
that any post-EndOfOptions Msg::Option would have tripped.
Contract documented in SetConfigHandler.hpp: lightningd delivers
Int/Bool/Flag option values as JSON primitives at startup but as JSON
strings at setconfig time, so dynamic-option handlers must accept both
Jsmn shapes.
