chore(build): keep only line tables in dev builds (#1260)

Full debug info made up most of target/: each worktree's build output was 15–30 GB. Dev builds now keep line tables for workspace crates (file:line stays in backtraces) and no debug info for dependencies, which brings a cold `cargo build` to about 9 GB and roughly halves cold build time. A debugger can't show locals any more; re-enable with `--config profile.dev.debug=true` when needed.

Co-authored-by: LittleGuava <[email protected]>

AGENTS.md

@@ -121,8 +121,8 @@ Several worktrees can be developed and run side by side.
   default MCP session belongs to this worktree.
 - Keep each worktree's Cargo output directory separate; do not point `CARGO_TARGET_DIR` or
   `target` symlinks at a shared directory.
-- Each worktree's first build is cold (around 5 minutes) and its Cargo output takes
-  15–30 GB. Avoid running several heavy builds on one machine at the same time.
+- Each worktree's first build is cold (several minutes) and `cargo build` output takes
+  around 9 GB; tests, clippy and incremental builds add more. Avoid running several heavy builds on one machine at the same time.
 - Stop only processes started for the current worktree/session. Never use broad
   process-name kills such as `pkill openidea`.
 - When done: stop that worktree's app and dev session, delete its build output, then

Cargo.toml

@@ -117,8 +117,14 @@ tempfile = "3"
 [profile.dev]
 # Keep debug builds snappy while giving dependencies decent speed.
 opt-level = 0
+# Full debug info is most of target/. Line tables keep file:line in our backtraces, but a
+# debugger can't show locals; re-enable with `--config profile.dev.debug=true`.
+debug = "line-tables-only"
 [profile.dev.package."*"]
 opt-level = 2
+# Dependency frames keep function names only. Re-enable one with
+# `--config 'profile.dev.package.<crate>.debug=true'`.
+debug = false
 
 [profile.release]
 codegen-units = 1