fix(loop): parallel hand-off + serial scope filter + summary in-flight + .hew.toml config (hew-zt4z, hew-s9mb, hew-cn2y, hew-c0pa)

[droidnoob]

Combines four follow-up branches from the autonomous loop run that closed hew-c0pa (project-local config epic) — three loop fixes plus the feature itself. Smoke-tested end-to-end before push.

Closes

• hew-zt4z P1 bug — parallel --jobs>=2 stranded tasks (dispatcher claimed, workers re-polled bd.ready() and saw empty)
• hew-s9mb P2 bug — serial --jobs=1 --scope=epics bypassed the scope filter at the worker's bd.ready() poll
• hew-cn2y P3 chore — hew loop summary errored with raw No such file when the run was in flight
• hew-c0pa P2 epic — project-local .hew.toml config file (+ 6 children)

Commits

commit	what
970f3dd	feat(config): discover_project_root + discover_project_config — pure fs walks for .beads/ then .git/; resolves worktrees to real repo root
be906ad	feat(config): load_layered + per-struct merge (hew-36of) — scalars: project wins; arrays: cargo-style concat-dedupe; tables: recurse
9f7b0c0	feat(init): emit starter .hew.toml after install (hew-3r8v) — embeds templates/hew.toml.starter; skips if a file already exists
16ee6e9	feat(config): config set --global/--project write-target (hew-k2gm) — refuses silent fallback when .hew.toml exists
397c5cd	feat(config): hew config show with per-key source provenance (hew-leh9)
69cd50e	docs(config): docs/CONFIG.md + CHANGELOG + CLAUDE cross-ref (hew-u181)
f192e44	fix(loop): render in-flight summary instead of ENOENT when run.json absent (hew-cn2y)
eae322b	fix(loop): apply Scope filter on serial path's bd.ready() poll (hew-s9mb)
2221c27	fix(loop): thread dispatcher pre-claim to worker so jobs>=2 actually runs (hew-zt4z)

Plus three merge commits stitching the four branches together. One textual conflict at hew/src/commands/loop_cmd.rs:1500-ish between the scope-filter and parallel-handoff branches — resolved by composing both (assign-then-filter, so the pre-claimed task still passes through the scope check for safety).

Smoke proof — both fixes verified end-to-end

Set up 4 ready tasks: hew-togn (smoke epic), hew-62c2 (P2 in epic), hew-44ge + hew-ybq3 (P1 standalones).

Test 1 — serial scope filter (hew-s9mb):

$ hew loop run --scope=epics --epics=hew-togn --dry-run --max-iter 1
iter 1 — task=hew-62c2 prefix_hash=b5521b8b0e7ace68
scope:     epics [hew-togn]

✓ Picked hew-62c2 (in-epic P2). The two higher-priority P1 standalones were never considered. Pre-fix this would have grabbed a P1.

Test 2 — parallel hand-off (hew-zt4z), real end-to-end:

Set up a 2-task epic with trivial "create a file, commit, close" tasks. Kicked the real loop (no --dry-run, real claude -p spawns, real worktrees at ~/.hew/wt/<run-id>/{0,1}/, real merge-back).

$ hew loop run --jobs=2 --scope=epics --epics=hew-omh2 --max-iter 2
(1m 50s wall, 3 iters)

per-worker:
  wkr   iters  closed runtime       tokens stop
  0         2       2 claude       936,962 max_iter
  1         1       1 claude       185,554 ready_empty
  all       3       3            1,122,516

outcomes:  3 closed
scope:     epics [hew-omh2]
planner:   agent=0, runtime=2, fallback=0
cache:     iter 2-3 hit (prefix_hash stable from iter 1)

End-state verification:

• All 3 tasks (epic + 2 children) actually closed in bd, not stranded in_progress.
• Both worker branches merged back to main: hew-core/SMOKE_A.txt and hew-core/SMOKE_B.txt both present in tree, each from a different worker's commit.
• manifest.json shows iter_count: 2 and iter_count: 1 for the two workers (pre-fix this was 0/0 with ready_empty).
• The batch planner ran twice between iters as designed (agent=0, runtime=2, fallback=0).
• hew loop summary mid-run rendered the in-flight view correctly (the hew-cn2y fix in action).

(Smoke commits + files cleaned out of this branch; only the fix code is in the PR.)

What the smoke fixed for the next time

Previous smoke (hew-mu5j in PR #58) tested only argv-parsing: --scope=bogus rejected, missing --scope errors with MissingFlag, etc. It never asserted "a scoped run claims only descendants" or "--jobs N actually drives N workers." That's why hew-zt4z and hew-s9mb shipped: those tests didn't exist.

This PR adds real-bd-graph smoke as a discipline, and the bug bodies + the test additions called out in hew-zt4z / hew-s9mb carry that forward as required test additions for any future loop change.

Gates

• cargo fmt --all --check ✓
• cargo clippy --all-targets -- -D warnings ✓
• cargo test --workspace ✓ (43 suites, 0 failed)
• Manual end-to-end smoke ✓ (above)
• bd-PATH parity (CI doesn't install bd; precheck guard from PR feat(loop): hew loop run --scope={ready|epics} flag (hew-b3yl) #58 still holds) ✓ implicitly via loop_scope_e2e 7/7

Net change

16 files changed, 2963 insertions(+), 11 deletions(-)

Largest contributor is hew-core/src/config.rs (+951) for the project-local config loader; otherwise it's well-scoped diffs across the loop + tests.

🤖 Generated with Claude Code

Smoke proof — .hew.toml feature

Verified after the loop-fix smoke (separate tempdir, fresh hew init):

$ hew init --non-interactive --runtime=claude
$ ls .hew.toml
.hew.toml          # ✓ starter emitted

$ head -7 .hew.toml
# hew project config — https://hew.sh/docs/config
# ...
version = 1
# [loop]
...

$ hew config set loop.model.default opus-4-7
Error: refusing to write to user-global config when `.hew.toml` exists ...
       Use one of:
         hew config set --project loop.model.default opus-4-7   # commit-shared
         hew config set --global  loop.model.default opus-4-7   # personal override
                                                                 # ✓ loud refusal

$ hew config set --project loop.model.default claude-opus-4-7
set loop.model.default = claude-opus-4-7 (...../.hew.toml)        # ✓ writes to project

$ hew config get loop.model.default
claude-opus-4-7                                                    # ✓ read-back

$ hew config show | grep loop.model.default
  loop.model.default = claude-opus-4-7              (project)      # ✓ provenance

All five concerns from the locked plan verified: starter emission, --project writes, refusal-when-project-exists-without-flag, get round-trip, show-with-source-attribution.