fix(engine): keep renderRepoMap's output within maxOutputChars including the marker (#9617)

[RealDiligent]

Problem

Closes #9617.

renderRepoMap (packages/loopover-engine/src/miner/repo-map.ts) is documented as a bounded outline that stops once maxOutputChars would be exceeded and appends a truncation marker. But pushLine budgets only the content lines — the marker was appended via lines.push unbudgeted:

if (truncated) lines.push("… (repo map truncated to fit the output budget)");

So a truncated result overshot maxOutputChars by up to the marker's length + a newline, and when the very first line already exceeded the budget it returned only the marker — a string longer than the budget with no content. maxOutputChars is a token-budget guarantee the prompt packet relies on.

Fix

Reserve the marker from the budget (extracted to a TRUNCATION_MARKER const):

• Not truncated → return the join unchanged (byte-for-byte identical, full budget, no reserved headroom).
• Truncated → drop trailing content lines until the marker (plus its joining newline while content remains) fits, then append it, so result.length <= maxOutputChars always.
• maxOutputChars < the marker's length → return the empty string rather than an over-budget marker.

Tests

test/unit/repo-map.test.ts: tightened the existing truncation test to the strict <= maxOutputChars bound; added a case asserting the bound holds across a spread of budgets (0, near/below/above the marker length, …) and that a sub-marker budget yields "" while a marker-sized budget yields the marker alone; updated the four break-site tests to the new contract (a below-marker budget truncates at each site to ""; the multi-symbol case keeps the fitting symbol alongside the reserved marker). 100% branch coverage on the changed file.

[loopover-orb]

Caution

🛑 LoopOver review result - fixes required

_{Review updated: 2026-07-29 01:23:53 UTC}

2 files · 1 AI reviewer · no blockers · CI failing · unstable

🛑 Suggested Action - Fix Blockers

Review summary
This PR reserves TRUNCATION_MARKER's length from renderRepoMap's budget so a truncated result never exceeds maxOutputChars, replacing the previous behavior where the marker was pushed unbudgeted and could overshoot by its own length plus a newline. I traced the new logic (early return for untruncated output, the maxOutputChars < marker.length guard, and the pop-until-fits loop) against the new test cases and it is correct: every traced scenario (budget 0, sub-marker, exactly-marker, marker+content) produces a result that respects the <= maxOutputChars invariant. The change is narrow, closes issue #9617 as required, and the multi-symbol retention test correctly exercises the content-preserving branch of the pop loop.

Nits — 4 non-blocking

• packages/loopover-engine/src/miner/repo-map.ts:341-345 — the new TRUNCATION_MARKER JSDoc block is inserted between the existing renderRepoMap doc comment and the function itself, so the original doc comment no longer directly precedes the function it documents (tooling that attaches JSDoc to the nearest following declaration will now attribute it to the const instead); move the marker's doc above the const and keep renderRepoMap's own doc comment immediately above `export function renderRepoMap`.
• The PR description claims '100% branch coverage on the changed file' but codecov/patch reports only 22.22% of the diff hit against a 99% target — worth double-checking that the coverage tool is actually picking up the new test cases in test/unit/repo-map.test.ts before merging.
• Verify locally that `pnpm test -- repo-map` plus the coverage reporter agrees with the PR's stated 100% branch coverage claim, since codecov/patch disagrees.
• Consider moving the TRUNCATION_MARKER JSDoc above the const declaration so it doesn't visually detach renderRepoMap's own doc comment from the function (repo-map.ts:341-345).

CI checks failing

• codecov/patch — 55.55% of diff hit (target 99.00%)

Decision drivers

• ✅ Code review — No blockers (1 reviewer)
• ✅ Gate result — Passing (No configured blocker found.)

Context & advisory signals — never blocks the verdict

Signal	Result	Evidence
Linked issue	✅ Linked	#9617
Related work	✅ No active overlap found	No same-issue or scoped active PR overlap found.
Change scope	✅ 20/20	Low review scope from cached public metadata (1 linked issue).
Validation posture	❌ 5/25	Preflight is holding this PR: the review lane is unavailable, so it is not ready for automated review.
Contributor workload	✅ 10/10	Author activity: 266 registered-repo PR(s), 111 merged, 37 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	RealDiligent; Gittensor profile; 266 PR(s), 37 issue(s).
Improvement	✅ Minor	risk: clean · value: minor · LLM: moderate

Linked issue satisfaction

Partially addressed
The core fix correctly reserves the marker's length (plus joining newline) from the budget, returns the unmodified string when nothing is truncated, and returns "" when maxOutputChars is smaller than the marker, all of which is exercised by new tests (empty-string case, multi-budget bound check, and updated break-site tests) — but the diff doesn't include the explicitly required new test asserting

Review context

• Author: RealDiligent
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository is registered but has no active allocation in the current snapshot.
• Public profile languages: Python, Ruby, TypeScript, Svelte, Cuda, JavaScript, Markdown, MDX
• Official Gittensor activity: 266 PR(s), 37 issue(s).
• PR-specific overlap: none found.

Contributor next steps

• Start here: Await review-lane availability.
• Then work through the remaining 2 steps in the Signals table above.

Signal definitions

• Related work = same linked issue, overlapping active PRs, or title/path similarity.
• Change scope = cached public metadata such as size labels, draft state, and review-burden hints.
• Validation posture = whether the PR provides enough public validation/test evidence for maintainer review.
• Contributor workload = public contributor activity and cleanup pressure, not a repo-wide quality failure.
• Contributor context = public GitHub/Gittensor identity context; non-Gittensor status is not a blocker.

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_{🟩 Safe / merged · 🟦 Advisory · 🟨 Held for review · 🟥 Blocked / closed}

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[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

❌ Patch coverage is 55.55556% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.01%. Comparing base (bd139a5) to head (7624ca6).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/loopover-engine/src/miner/repo-map.ts	55.55%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9623      +/-   ##
==========================================
- Coverage   90.02%   90.01%   -0.01%     
==========================================
  Files         888      888              
  Lines      111983   112000      +17     
  Branches    26570    26573       +3     
==========================================
+ Hits       100810   100815       +5     
- Misses       9843     9851       +8     
- Partials     1330     1334       +4     

Flag	Coverage Δ
backend	95.56% <100.00%> (-0.01%)	⬇️
engine	66.53% <22.22%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
packages/loopover-engine/src/miner/repo-map.ts	66.00% <55.55%> (-0.58%)	⬇️

... and 1 file with indirect coverage changes

[loopover-orb]

LoopOver is closing this pull request on the maintainer's behalf (CI is failing (codecov/patch)). This is an automated maintenance action — to pursue this change, please open a new pull request with the issues resolved. Closed PRs may be analyzed later to improve review accuracy, but they are not automatically reopened or re-reviewed.