GeezerVison

Part of CODAGT-1341.

This layer prepares chatd for a third skill source without loading it yet. coderd/x/skills gains SourceOrganization = "org", and MergeSkills becomes one merge over personal, org and workspace lists in that order, sorted by name. A name in one source keeps its bare alias; a name in several sources gets a qualified alias (personal/x, org/x, workspace/x) in every source that has it, so no source overrides another. Lookup still rejects an ambiguous bare name with ErrSkillAmbiguous. chatd passes nil for the org list; the next layer fills it.

• The <available-skills> index cuts descriptions over 1,024 runes (the Agent Skills spec limit) on a rune boundary and adds …. Stored descriptions and the API keep the full text.
• Skill parse and lookup errors put the wrapped sentinel last, so the cause is not repeated. The qualified-alias hint no longer names only two sources: "When a skill is listed with a source prefix, such as personal/name, pass that qualified alias to read_skill."
• read_skill loads personal and org skills through one source-aware ReadSkillOptions.LoadStoredSkillBody, which replaces LoadPersonalSkillBody. read_skill_file reports that any non-workspace skill has no supporting files.

Behavior change for existing personal skills: rows with enabled = false are left out of the index, and read_skill returns not found for them.

Testing

• TestMergeSkills (every collision shape, qualified lookups, an ambiguous bare lookup naming the sentinel once, bare aliases without collisions), TestLookup (org/x), and TestFormatResolvedSkillIndex (three-source output, the exact hint line, and TruncatesLongDescriptionsOnRuneBoundary with 3-byte runes at and over the limit).
• TestReadSkillTool/OrganizationSkillUsesStoredLoader, TestReadSkillFileTool/StoredSkillUnsupported, TestFetchPersonalSkillMetadata with a disabled row, and TestLoadPersonalSkillBody/DisabledSkill.
• Red-green: the tests fail if the org source is never qualified, if truncation is removed or done by byte, if the org case leaves the read_skill switch, or if either personal enabled check is removed.
• Ran go build ./..., the coderd/x/skills, chattool and chatd skill tests, golangci-lint on the touched packages, and make pre-commit.

Review record

• Remote UAT round 6 through Coder Agents: PASS on the final stack tip afdd4a9f954 (chat); its low notes are in docs(docs/ai-coder/agents): document organization skills #30604.
• Codex round 1: declined trimming truncated index descriptions to 1,023 runes, because the index only previews descriptions that may be stored longer and the ellipsis marks the cut.

This stack adds organization skills to Coder Agents: admins publish a skill once per organization, share it with groups or members, and chats in that organization load it next to personal and workspace skills.
Stack, bottom to top: #30584, #30585, #30586, #30587, #30588, #30589, #30590, #30591, #30592, #30593, #30594, #30595, #30596, #30597, #30598, #30599, #30600, #30601, #30602, #30603, #30604.

Xum opened this PR on behalf of @ibetitsmike.