DevFlow: logs --follow --source all filters out ordinary log sources #653

Summary

maui devflow logs --source all and maui devflow logs --follow --source all interpret the same CLI option differently. One-shot reads treat lowercase all as no source filter, while follow mode sends the literal filter source=all, excluding logs from ordinary sources.

Found during the baseline contract audit associated with #652. That PR is spec-only and does not fix this bug.

Reproduction

With one DevFlow agent selected/connected and buffered or newly emitted logs whose source is not literally all:

1. Run maui devflow logs --source all: ordinary sources are included.
2. Run maui devflow logs --follow: replay/live entries from ordinary sources are included.
3. Run maui devflow logs --follow --source all: those entries are filtered out. Stop follow commands with Ctrl+C between comparisons.

Expected: Explicit --source all behaves like omitting the source filter in both one-shot and follow modes, including replay and newly emitted entries.

Actual: Follow mode selects only entries whose producer source is named all, commonly producing no entries.

This is a source-verified finding; a device-level end-to-end reproduction was not performed during the audit.

Baseline source evidence

Evidence is pinned to pre-implementation commit 64e8e90c6921e68cdb2747530b58dd528dd57578:

• AgentClient.GetLogsAsync omits the HTTP source query when source == "all".
• MauiLogsFollowAsync adds every nonempty source, including all, to the WebSocket query.
• HandleLogsWebSocket passes the source filter to replay reads and compares live entry sources literally, case-insensitively.
• FileLogReader applies the producer-source filter to replay entries.

Acceptance criteria

• Align CLI follow-mode handling of lowercase --source all with existing one-shot behavior.
• Cover unfiltered, explicit all, and ordinary source-filtered behavior for both replay and live entries.
• Preserve real source filtering and the existing agent wire contract; do not introduce an unrelated protocol change.
• Demonstrate the corrected CLI behavior against a connected agent.