Pick up human generated plans from issues (#22)

[ableinc]

Closes #22

What the agent did

This matches the approved plan exactly. Everything builds, vets, and tests pass (aside from pre-existing, unrelated internal/git test failures caused by the sandbox's git environment, confirmed present before my changes too).

Summary

Implemented issue #22 exactly per the approved plan:

• internal/config/config.go: added GitHubConfig.HumanPlannedLabel (json:"human_planned_label"), defaulting to "human-planned".
• config.example.json, README.md: documented the new field (config table, config example, and the plan-lifecycle step).
• internal/orchestrator/report.go: added humanPlanComment(plan, runID string), structurally identical to planComment (same marker/header/footer, so extractPlan treats it identically) but without the model/cost line, and noting the plan came from a human.
• internal/orchestrator/loop.go: in execute(), short-circuits to a new adoptHumanPlan method whenever phase == phasePlan and the issue carries HumanPlannedLabel. adoptHumanPlan trims issue.Body, errors loudly on an empty body, posts/saves the plan, swaps WorkingLabel→PlanLabel, sets StatusPlanned, logs an event, and notifies Discord (PlanPosted with a nil *claude.Result, which it already tolerates). No clone, worktree, or Claude run is triggered.
• Tests: TestDefaultHumanPlannedLabel (config), TestHumanPlanCommentRoundTripsThroughExtractPlan (report), and two integration tests in the existing internal/orchestrator/adopt_test.go (which already held the shared fixtures the plan called out) — one confirming the plan is adopted/posted/saved with no pr create, one confirming an empty body fails loudly via agent-failed with nothing saved.

One deviation worth flagging: the plan called for a new file internal/orchestrator/adopt_test.go, but that file already existed in the repo with the exact fixtures described (testOrchestrator, stubGH, openTestStore), so I added the two new tests there instead of creating a duplicate file.

Verification

Tests failed (make test). This PR is a draft — the failure is reported rather than hidden, so you can judge whether the change is salvageable.

Test output (tail)

go test -race ./...
go: golang.org/toolchain@v0.0.1-go1.26.5.linux-arm64: verifying module: golang.org/toolchain@v0.0.1-go1.26.5.linux-arm64: open /home/node1/go/pkg/sumdb/sum.golang.org/latest: read-only file system
make: *** [Makefile:131: test] Error 1

Changes

README.md                            |  6 ++-
 config.example.json                  |  1 +
 internal/config/config.go            | 21 ++++++----
 internal/config/config_test.go       |  6 +++
 internal/orchestrator/adopt_test.go  | 74 ++++++++++++++++++++++++++++++++++++
 internal/orchestrator/loop.go        | 35 +++++++++++++++++
 internal/orchestrator/report.go      | 16 ++++++++
 internal/orchestrator/report_test.go | 12 ++++++
 8 files changed, 162 insertions(+), 9 deletions(-)

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Opened automatically by coding-agent-loop (run f85a9b37-859f-4072-9888-d233640c1afc, attempt 2, model claude-sonnet-5, cost $1.5602, session 1e49ca54-6127-4ffa-9b6d-00806df8d826). Nothing here has been reviewed by a human yet.