fix(ledger): read the line budget in command position, and read sed ranges

[fajarhide]

Two errors at opposite ends of one function, both found within a day of #737 shipping it.

rations_its_output matched head or tail anywhere in the string, so grep -rn head src/ and ls | grep tail turned the project scope off for the whole reply (#738). And it covered head and tail only, so sed -n 60,200p of a source file fell straight through: 28 lines of a JSX render branch folded on the file's first appearance in a cleared context, with the next step being an edit to that render path (#741). An edit written against a marker is worse than a wasted retrieval.

The name now counts only in command position, and sed addresses that name line numbers count. A pattern address and a substitution do not, because those filter, which is a different claim from naming the lines wanted.

Driving the built binary through --post-hook, same store, same primed block, same payload, only the command differing. Three arms must not fold and three must:

sed -n 60,200p app/run-panel.tsx      no rewrite     #741
sed -n '60,200p' app/run-panel.tsx    no rewrite     #741, quoted
cat notes.md; echo ---; tail -5 x     no rewrite     #735, still works
grep -rn head src/                    folds          #738
sed -n '/failed/p' build.log          folds          a pattern is not a line budget
cat handlers.log                      folds          the feature is intact

make ci green. Four break tests, each with its diff proven before the run: command-position guard removed, sed arm removed, sed address check neutered, and the -c/-f exclusion removed. All four went red.

awk is deliberately uncovered and its negative case is in the test, so a future change that starts matching it is a decision rather than a side effect. Its line selection is an expression rather than a flag, and the obvious guess matches {print NR}, which prints line numbers rather than selecting them.

One known limit, stated rather than hidden: a separator glued to the following token (cat a.md;tail -5 b) is not recognised and folds as before. Agents write the spaced form, and a tokeniser is a larger thing than this predicate deserves.

Closes #738, closes #741

Greptile Summary

The PR narrows line-budget detection to command position and adds numeric sed address recognition so ledger project folding does not hide explicitly requested lines.

• Adds command-boundary classification for head, tail, and sed.
• Recognizes quoted and unquoted numeric sed print addresses.
• Adds regression coverage and changelog entries for issues rations_its_output accepts head/tail in argument position, so grep -rn head src/ turns off the project scope (#737 follow-up) #738 and Ledger folds 28 lines of a source file on its first appearance in a cleared context: project-scope 'already shown' outlives the context that saw them (0.7.8) #741.

Confidence Score: 4/5

The wrapped-command regression should be fixed before merging because it can again hide explicitly selected lines behind a project-history marker.

The command-position predicate excludes realistic wrapper-prefixed head, tail, and sed invocations, bypassing the guard added to preserve line-budgeted output; the sed scan also crosses command boundaries and can unnecessarily disable folding.

Files Needing Attention: src/ledger/mod.rs

Important Files Changed

Filename	Overview
src/ledger/mod.rs	Adds command-position and numeric-sed parsing, but wrapped selectors bypass the preservation guard and the sed argument scan crosses command boundaries.
changelog.d/738.fixed.md	Documents the command-position false-positive correction and its intentional glued-separator limitation.
changelog.d/741.fixed.md	Documents preservation of output selected by numeric sed addresses.

Prompt To Fix All With AI

### Issue 1
src/ledger/mod.rs:947-949
**Wrappers bypass line-budget detection**

When `head`, `tail`, or `sed` is invoked through a supported wrapper such as `docker exec app tail -5 app.log`, `opens_a_command` rejects the selector because its preceding token is not a shell separator. The project-fold guard then fails to preserve the explicitly selected lines, causing them to be replaced by a retrieval marker in compound output.

### Issue 2
src/ledger/mod.rs:954-955
**Sed scan crosses command boundaries**

For a command such as `sed -n '/failed/p' build.log; echo 5p`, the `sed` branch scans every remaining token and mistakes the later command's `5p` argument for a numeric sed address. This unnecessarily disables project folding for the entire payload and consumes context with repeated output.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "docs(changelog): record the command-posi..." | Re-trigger Greptile}

Greptile also left 2 inline comments on this PR.

[greptile-apps]

Wrappers bypass line-budget detection

When head, tail, or sed is invoked through a supported wrapper such as docker exec app tail -5 app.log, opens_a_command rejects the selector because its preceding token is not a shell separator. The project-fold guard then fails to preserve the explicitly selected lines, causing them to be replaced by a retrieval marker in compound output.

Knowledge Base Used: Restore command-aware ledger folding

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/ledger/mod.rs
Line: 947-949

Comment:
**Wrappers bypass line-budget detection**

When `head`, `tail`, or `sed` is invoked through a supported wrapper such as `docker exec app tail -5 app.log`, `opens_a_command` rejects the selector because its preceding token is not a shell separator. The project-fold guard then fails to preserve the explicitly selected lines, causing them to be replaced by a retrieval marker in compound output.

**Knowledge Base Used:** [Restore command-aware ledger folding](https://app.greptile.com/weekndlabs/-/custom-context/knowledge-base/fajarhide/omni/-/reverts/incident-mitigation_737-20260830-command-budgeted-output-cdc73f6.md)

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

[greptile-apps]

Sed scan crosses command boundaries

For a command such as sed -n '/failed/p' build.log; echo 5p, the sed branch scans every remaining token and mistakes the later command's 5p argument for a numeric sed address. This unnecessarily disables project folding for the entire payload and consumes context with repeated output.

Knowledge Base Used:

• Graphs, ledger, and context analytics
• Restore command-aware ledger folding

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/ledger/mod.rs
Line: 954-955

Comment:
**Sed scan crosses command boundaries**

For a command such as `sed -n '/failed/p' build.log; echo 5p`, the `sed` branch scans every remaining token and mistakes the later command's `5p` argument for a numeric sed address. This unnecessarily disables project folding for the entire payload and consumes context with repeated output.

**Knowledge Base Used:**
- [Graphs, ledger, and context analytics](https://app.greptile.com/weekndlabs/-/custom-context/knowledge-base/fajarhide/omni/-/docs/graphs-ledger-and-context-analytics.md)
- [Restore command-aware ledger folding](https://app.greptile.com/weekndlabs/-/custom-context/knowledge-base/fajarhide/omni/-/reverts/incident-mitigation_737-20260830-command-budgeted-output-cdc73f6.md)

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.