Fix Penalties popup data + concurrent Nostr relay callback corruption

[dangershony]

Summary

Two related fixes from the same investigation, kept as separate commits:

1. Penalties popup showed stale/incorrect data

The Funded > Penalties button opened a modal that filtered the already-loaded Investments list by a per-investment \RecoveryState\ flag only populated lazily when a user opens that specific investment's detail view (Manage). If you never drilled into a project with a penalty, it silently never showed up in the popup. Separately, once wired to the correct SDK operation, the displayed 'days remaining' was always a hard-coded 365-day placeholder due to an unrelated SDK bug.

• \PortfolioViewModel: added \LoadPenaltiesAsync(), calling the SDK's wallet-wide \GetPenalties\ operation (previously only used by the CLI) into a new \Penalties\ collection, replacing \PenaltyInvestments/\HasPenaltyInvestments.
• \PortfolioView: Penalties button now triggers a fresh scan instead of reading stale in-memory state.
• \PenaltiesModal: bound to the new collection, added a loading state, now shows the resolved project name alongside the project ID.
• \GetPenalties\ (SDK): fixed \LookupInvestment.Project\ never being populated (causing the 365-day placeholder), and excluded penalties that were already fully released from the results.
• Updated the two \App.Test.Integration\ tests that asserted on the removed properties.

2. Concurrent Nostr relay callbacks corrupting consumer state

\RelayService\ connects to multiple relays simultaneously and merges their events into a single shared Rx subject per client, with nothing serializing delivery to subscribers. When two relays responded around the same instant, a subscriber's callback could be invoked concurrently from two different relay receive threads.

This surfaced while running the UAT suite: concurrent writes to a plain \Dictionary/\HashSet/\List\ in \DocumentProjectService\ threw 'Operations that change non-concurrent collections must have exclusive access', corrupting the collection and causing 'No projects found in Nostr relays' for the rest of that process's life — blocking project discovery for that investor.

Rather than patch every consumer that mutates shared state inside a relay callback (a scan turned up several more instances of the same bug shape, including in the legacy webapp), this fixes it once at the source: every \RelayService\ \EventStream\ subscription and every \RelaySubscriptionsHandling\ \OkStream/\EoseStream\ subscription is now wrapped with Rx's \Synchronize()\ operator, guaranteeing non-overlapping delivery to each subscriber's callback regardless of how many relays respond at once. \DocumentProjectService\ itself needed no changes since the guarantee now holds upstream.

Testing

• \dotnet build\ on \Angor.Sdk, \Angor.Shared, \Angor.Client\ (webapp), \App\ (Avalonia class library), and \App.Test.Integration\ — all green.
• Ran the UAT suite (\CreateProjectTest, \MultiFundClaimAndRecoverTest, \MultiInvestClaimAndRecoverTest): \CreateProjectTest\ passed; the other two hit the relay race (now fixed) on the first run, and on retry were blocked by the shared signet faucet returning 503/no UTXOs available — external infrastructure, unrelated to this change.
• Manually verified the Penalties popup fix against a real signet penalty.