feat: add projects command and issues --project filter

[seraph-pixelperfect]

Closes #20
Depends on #38 (this branch is stacked on feat/multi-label-pagination, itself stacked on #37)

What

• linear-axi projects — lists workspace projects via the root projects connection: name, state, progress, lead, target (target date), most recently updated first, auto-paginated in 50-size batches exactly like fetchIssues (same cursor guards).
• linear-axi issues --project <name> — composes project: { name: { eq: ... } } into the existing IssueFilter builder in fetchIssues, so it works on both the plain issues query and the searchIssues path (composes with --team, --state, --label, --search). A missing/blank --project value is rejected loudly (same guard class as --search), never silently dropped.
• resolveProjectId(name) helper in src/linear.ts, mirroring resolveTeamId (projects(filter: { name: { eq: $name } })). Not wired into any command yet — reserved for v0.3 write-side project assignment per the issue; covered by tests now.

Schema verification (source: generated types in @linear/sdk 90.0.0)

Verified by npm pack @linear/sdk and inspecting the generated documents (dist/index-zxW4m1xd.d.mts, dist/index.mjs):

• Root projects query exists with the same connection args as issues: filter: ProjectFilter, first: Int, after: String, orderBy: PaginationOrderBy (ProjectsDocument in dist/index.mjs; ProjectConnection { nodes, pageInfo }).
• IssueFilter.project?: NullableProjectFilter ("Filters that the issues project must satisfy"), and NullableProjectFilter.name?: StringComparator with eq — this is the comparator behind issues --project. Same for ProjectFilter.name (used by resolveProjectId).
• Project.progress: Float — "(completed estimate points + 0.25 * in progress estimate points) / total estimate points", i.e. a 0–1 float.
• Project.lead?: Maybe<User> — "Null if no lead is assigned"; User.name is what we select.
• Project.targetDate?: Maybe<TimelessDate> — null when unset; Linear serializes TimelessDate as a YYYY-MM-DD date string (rendered raw).

Ambiguities / decisions flagged

1. state vs status: the issue says "state is an enum (ProjectState)". In the current schema Project.state: String is deprecated ("Use project.status instead"), and there is no ProjectState type — the values live on ProjectStatus.type: ProjectStatusType (backlog, planned, started, paused, completed, canceled). We query status { type } and render it as state with the raw lowercase value the issue asked for — same rendered output, no deprecated field. Renaming the output column to status later would be a one-liner.
2. Progress rendering: chosen as an integer percent 0–100 (e.g. 0.42 → 42), documented in projects --help ("percent complete, 0-100"). Raw float was the alternative; percent reads better in TOON and is documented.
3. Nulls: lead and targetDate are nullable; both render as none (matching the repo's existing empty-render convention from joinArray).

Demo (before/after)

pnpm exec tsx bin/linear-axi.ts ... --key lin_api_fake — the fake key is rejected by the real API, which proves the commands reach the API layer; LINEAR_AXI_DEBUG=1 dumps the emitted document.

Before (base 230c540):

$ pnpm exec tsx bin/linear-axi.ts projects --key lin_api_fake
error: "Unknown command: projects"
code: VALIDATION_ERROR

$ pnpm exec tsx bin/linear-axi.ts issues --project "Mobile app" --key lin_api_fake
error: unknown flag --project
code: VALIDATION_ERROR
help[1]: "valid flags: --team, --state, --assignee, --label, --search, --limit (--help always allowed)"

After:

$ pnpm exec tsx bin/linear-axi.ts projects --key lin_api_fake   # LINEAR_AXI_DEBUG=1
[linear-axi] query: query Projects($first: Int!, $after: String) {
    projects(first: $first, after: $after, orderBy: updatedAt) {
      nodes { id name status { type } progress lead { name } targetDate }
      pageInfo { hasNextPage endCursor }
    }
  }
[linear-axi] variables: {"first":50}
error: Linear auth required — set LINEAR_API_KEY or pass --key <key>   # fake key rejected by api.linear.app
code: AUTH_REQUIRED

$ pnpm exec tsx bin/linear-axi.ts issues --project "Mobile app" --team LIN --state started --key lin_api_fake
issues(filter: { team: { key: { eq: "LIN" } }, state: { type: { eq: "started" } }, project: { name: { eq: "Mobile app" } } }, first: $first, after: $after, orderBy: updatedAt) { ... }
error: Linear auth required ...   # reached the API layer

$ pnpm exec tsx bin/linear-axi.ts issues --search crash --project "Mobile app" --key lin_api_fake
searchIssues(term: $term, filter: { project: { name: { eq: "Mobile app" } } }, first: $first, after: $after) { ... }
# composes on the search path too

$ pnpm exec tsx bin/linear-axi.ts projects --help
usage: linear-axi projects
	List the projects in your Linear workspace, most recently updated first.

columns:
  name     project name
  state    lifecycle state: backlog, planned, started, paused, completed, canceled
  progress percent complete, 0-100
  lead     project lead (none if unassigned)
  target   target date as YYYY-MM-DD (none if unset)

Local gates (all run on the pushed commit c8a0fbf)

• pnpm build — clean (tsc, exit 0)
• pnpm lint — clean (eslint ., exit 0)
• pnpm run build:skill -- --check — skills/linear-axi/SKILL.md is up to date. (TOP_HELP command list + skill description/workflow updated, regenerated)
• pnpm test:

 Test Files  9 passed (9)
      Tests  78 passed (78)

(63 → 78; +15 in the new test/projects.test.ts)

• pnpm run format:check — RED pre-existing on the base branch (18 files) and unchanged by this PR (still exactly the same 18; the two new files pass pnpm exec prettier --check). Not enforced in CI.

Stacked-PR / CI note

Stacked on #38 (which is stacked on #37). No CI checks will appear on this PR — ci.yml only triggers on PRs targeting main. CI runs when retargeted to main after #38 and #37 merge; local gates pasted above are the evidence. Not retargeting.

CI quota-block caveat: org billing/spending-limit rejections can look like check failures in gh pr checks; if a check is red, check gh run view <run-id> for a billing annotation or the jobs API for empty steps + ~3-4s duration before assuming breakage. Jobs are not retried.

Identity

Automated agent dispatch authenticated as seraph-pixelperfect, submitted for human review — not self-approved. Merge is a human decision.

[ghostinprod-pixelperfect]

Superseded by merged rc/0.1 PR #51 (commit 694a564), which consolidated this read/discovery stack with validation and review fixes.