fix(server): install telemetry as the FIRST step of boot, not the last

[jrosskopf]

Problem

Telemetry used to install inside serve(), which EscurelConfig::build() calls only after doing all the real boot work (LaneStore, embedder, DuckLake attach, the writer lease, #563's lake adoption). Every log line from that entire sequence was silently dropped — no subscriber existed yet to capture it.

Found chasing exactly that: #563's new "writer boot: adopted existing lake content before serving" log never appeared on lab despite other, independent evidence (the periodic publish task's dirty-check correctly skipping its first tick) proving the adoption code was genuinely running. Confirmed via git show <deployed-sha> that the log statement really was in the shipped binary — this was a boot-ordering gap, not a bug in #563's fix itself.

Fix

install_telemetry now takes just a version string (all it ever read off ServerConfig) and EscurelConfig::build calls it as literally its first statement, before anything else. The resulting guard threads through to serve(), which now accepts an already-installed guard instead of always installing its own — falling back to installing one itself (None → install) for a caller that reaches serve() without going through build(), preserving existing behaviour there. Updated the one such caller (escurel-test-support's process harness, which constructs ServerConfig directly) to pass None explicitly.

No functional change to anything build() does — same steps, same order — only when logging becomes possible relative to them.

Testing

Full suite: escurel-index 224/224, escurel-server 444/444 — no regressions, including telemetry_filter.rs (whose EscurelProcess harness bypasses build() and now exercises the new None-fallback path). cargo clippy --all-targets -- -D warnings and cargo fmt --check both clean across the workspace.

Plan after merge: deploy to lab and confirm the #563 adoption log line (and everything else from early boot) finally shows up in a real pod's logs.

🤖 Generated with Claude Code

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