Build with line tables only: a test build no longer runs Tower out of memory

Linking ipx's 431 MB test binary took Tower, 31 GB with no swap and 4 GB free
beside its containers, into page-fault thrashing for 54 minutes: load 160 with
the CPU idle and 130 processes blocked. Line tables for our crates and no debug
info for dependencies make it 109 MB, built in 2m14s with load at 20 and 6.5 GB
left. CLAUDE.md says to watch memory beside the load.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Cargo.toml

@@ -42,3 +42,12 @@ tracing = "0.1.44"
 tracing-opentelemetry = { version = "0.34", default-features = false }
 tracing-subscriber = { version = "0.3.23", features = ["env-filter", "json"] }
 url = "2.5.8"
+
+# Backtraces keep file and line; the full debug info made a 431 MB test binary whose link ran
+# Tower, which has no swap, out of memory and stalled it for most of an hour (2026-10-18).
+[profile.dev]
+debug = "line-tables-only"
+
+# Nobody steps through dependencies.
+[profile.dev.package."*"]
+debug = false