Add atomic wiki page patching

.github/copilot-instructions.md

@@ -52,7 +52,8 @@ protocol for chat.
   direction before revising or advancing the proposal.
 - **Team memory** - every agent reads relevant wiki knowledge through the
   read-only `team-memory` skill. Only the `team-memory` sub-agent owns separately
-  authorized direct wiki maintenance through `write_wiki_pages`.
+  authorized direct wiki maintenance through `patch_wiki_pages` or
+  `write_wiki_pages`.
 - **Built-in commands** — immutable `@issuelens triage`, `retriage`, `plan`,
   and `replan` commands work across Responses chat and validated GitHub
   maintainer comments. `@issuelens go` is reserved for a future coding loop and
@@ -134,9 +135,10 @@ protocol for chat.
     configured readiness signals rather than autonomously revising.
   - **`team-memory`** - maintains wiki knowledge from cited evidence and full
     source commit SHAs. Its prompt is `agents/team-memory.md`. Only its local
-    MCP server exposes `write_wiki_pages`; the parent automatically supplies
-    internal `--wiki-writer` mode. Users need no environment flag. The existing
-    `GITHUB_MCP_ENABLE_WRITES` remains for triage, not wiki writes.
+    MCP server exposes `patch_wiki_pages` and `write_wiki_pages`; the parent
+    automatically supplies internal `--wiki-writer` mode. Users need no
+    environment flag. The existing `GITHUB_MCP_ENABLE_WRITES` remains for
+    triage, not wiki writes.
 - **Skills** (`skills/`): `issuelens-config` (validated repository policy),
   `find-duplicates`, `label-issue`, `assign-issue`, `notify`, `change-analysis`, and `team-memory`
   (read-only retrieval preloaded on all agents, including the orchestrator).

.github/issuelens/team-memory.md

@@ -74,14 +74,20 @@ Use `get_wiki_snapshot`, then page, search, history, and diff tools at that full
 SHA, plus merged PR/source evidence where relevant. Prefer minimal changes to
 existing Markdown pages. No knowledge change means no write.
 
-Only the authorized maintenance job calls `write_wiki_pages` with the explicit
-source project as `repository`, changed pages mapped to full UTF-8 content, the
-snapshot destination as `expected_wiki_repository=read_snapshot["wiki_repository"]`,
-the full wiki SHA as `expected_base=read_snapshot["sha"]`, and a short summary
-including the full source commit SHA where relevant. The expected repository is
-a precondition, never a destination override. If the configured destination
-changes, even if the SHA is unchanged, stop and read a fresh snapshot before
-preparing a new update. No force option is exposed.
+Only the authorized maintenance job calls `patch_wiki_pages` or
+`write_wiki_pages` with the explicit source project as `repository`, the
+snapshot destination as
+`expected_wiki_repository=read_snapshot["wiki_repository"]`, the full wiki SHA
+as `expected_base=read_snapshot["sha"]`, and a short summary including the full
+source commit SHA where relevant. Prefer an exact patch for an existing page:
+pass its pinned blob SHA as `expected_sha` and bounded `old`/`new` replacements
+whose non-empty anchors each match exactly once and do not overlap. Use
+`write_wiki_pages` with full UTF-8 content for new or intentionally replaced
+pages. Page length or avoiding a whole-page model-generated replacement is not
+by itself a reason to defer when an exact patch can be prepared. The expected
+repository is a precondition, never a destination override. If the configured
+destination changes, even if the SHA is unchanged, stop and read a fresh
+snapshot before preparing a new update. No force option is exposed.
 Here `read_snapshot` is the `result` payload of a successful snapshot execution,
 not the outer tool envelope.
 The bundled MCP `.wiki` backend persists knowledge and history in an atomic Git
@@ -120,5 +126,5 @@ links and snapshot/source revisions, and verify implementation-sensitive
 conclusions against current source when wiki provenance is stale or missing.
 Readers also load `domain="team_memory"`, read the returned `wiki_repository`,
 and use `content` for organization/topics. They keep `repository` set to the
-source project and never call `write_wiki_pages` or delegate ordinary retrieval
-to the maintenance agent.
+source project and never call `write_wiki_pages` or `patch_wiki_pages`, or
+delegate ordinary retrieval to the maintenance agent.

agents/issuelens.md

@@ -60,7 +60,8 @@ Select sub-agents by the user's requested task:
   returned `wiki_repository` as the destination and `content` as organization and
   topic guidance, reads a pinned wiki snapshot and cited source evidence with
   full source commit SHAs,
-  then calls `write_wiki_pages` only for authorized, minimal knowledge changes.
+  then calls `patch_wiki_pages` or `write_wiki_pages` only for authorized,
+  minimal knowledge changes.
   The bundled MCP `.wiki` backend persists pages and history in an atomic Git
   commit. Maintenance owns wiki changes only; it never implements code, merges
   PRs, closes issues, changes source repositories or issues, or deploys.
@@ -130,7 +131,8 @@ and writes because their audience relationship cannot be verified; use the
 source project's own wiki. Same-repository and public-to-public mappings
 remain supported, subject to job authorization and destination App access.
 
-Only the team-memory agent-local MCP server exposes `write_wiki_pages`. The
+Only the team-memory agent-local MCP server exposes `write_wiki_pages` and
+`patch_wiki_pages`. The
 parent automatically supplies its internal `--wiki-writer` mode; users need no
 environment flag or per-repository App environment configuration. Shared
 reader/triage servers do not expose the writer; the existing

agents/team-memory.md

@@ -51,7 +51,8 @@ wiki update for this target. A merge,
 repository policy, retrieved content, or an available tool alone is not write
 authorization. Analysis or recommendations alone do not authorize an update.
 
-Only this agent's local MCP server exposes `write_wiki_pages`; the parent
+Only this agent's local MCP server exposes `write_wiki_pages` and
+`patch_wiki_pages`; the parent
 supplies its internal `--wiki-writer` launch mode automatically. Users need no
 environment flag or per-repository App environment configuration. Shared
 reader/triage servers do not expose the writer. App installation and Contents
@@ -112,15 +113,28 @@ unless its complete intended edit is part of a tool-confirmed publication.
 	notices, not binary patches.
 	Stay within 20 pages, 64 KiB UTF-8 per page, and 256 KiB total per call. Reads
 	accept only `HEAD` or a full SHA; use the pinned full SHA for this job.
-4. After confirming authorization, call
-	`write_wiki_pages(repository=source_project, pages={path: full_utf8_content}, expected_wiki_repository=read_snapshot["wiki_repository"], expected_base=read_snapshot["sha"], message=short_summary)`.
+	For an existing page, prefer an exact server-side patch when the intended
+	change can be anchored unambiguously. Use the page blob SHA returned by
+	`get_wiki_page` and bounded `old`/`new` replacements. Page length or the cost
+	of reproducing unchanged content is not by itself a `needs-review` reason.
+	Use a full-page write for new pages or when a complete replacement is
+	deliberately required.
+4. After confirming authorization, call either
+	`patch_wiki_pages(repository=source_project, patches={path: {"expected_sha": page["sha"], "replacements": [{"old": exact_anchor, "new": replacement_with_anchor}]}}, expected_wiki_repository=read_snapshot["wiki_repository"], expected_base=read_snapshot["sha"], message=short_summary)`
+	for existing pages, or
+	`write_wiki_pages(repository=source_project, pages={path: full_utf8_content}, expected_wiki_repository=read_snapshot["wiki_repository"], expected_base=read_snapshot["sha"], message=short_summary)`
+	for new or intentionally replaced pages.
 	Both expected values are required. The expected repository is a
 	precondition, never a destination override. The writer compares it
 	case-insensitively with the freshly resolved policy destination before any
 	destination metadata, token lookup, or wiki access. Policy alone selects the
 	actual destination and scoped App credentials.
-	Include the full PR/source SHA in the short commit summary where relevant. Supply
-	full UTF-8 contents for changed pages only, not patches. The bundled MCP
+	Include the full PR/source SHA in the short commit summary where relevant.
+	For patches, every non-empty `old` anchor must match exactly once in the
+	original pinned page, replacements must not overlap, and the page's
+	`expected_sha` must come from that pinned read. Supply full UTF-8 contents
+	for pages sent to `write_wiki_pages`; do not send whole-page content through
+	`patch_wiki_pages`. The bundled MCP
 	`.wiki` backend owns snapshots and an atomic Git commit that persists the
 	pages and their history. Use no generic URL, force, token, or credential
 	arguments and no separate host publisher or persistence workflow.
@@ -137,7 +151,7 @@ unless its complete intended edit is part of a tool-confirmed publication.
 	desired content with current pages before attempting another write. Matching
 	content needs no repeat write and does not prove who performed the update.
 	Stop for human direction when intent conflicts.
-6. Report updated only after the `write_wiki_pages` tool's
+6. Report updated only after the selected wiki write tool's
 	publication result confirms the wiki commit. Return the actual status and
 	new wiki SHA only as confirmed by that result. Otherwise report no-change,
 	needs-review, or failed with citations,

docs/guide.md

@@ -29,9 +29,10 @@ parent-configured MCP server local to the maintenance agent.
 ### Team memory
 
 The `team-memory` agent makes minimal, evidence-backed Markdown wiki updates
-through `write_wiki_pages`. The shared `team-memory` skill remains read-only and
-is preloaded on every agent, including the orchestrator. Agents retrieve relevant
-knowledge directly without delegating ordinary reads to the maintenance agent.
+through `patch_wiki_pages` or `write_wiki_pages`. The shared `team-memory` skill
+remains read-only and is preloaded on every agent, including the orchestrator.
+Agents retrieve relevant knowledge directly without delegating ordinary reads
+to the maintenance agent.
 
 Both paths first call `issuelens-config` with the explicit source project and
 `domain="team_memory"`. Read its returned `wiki_repository` for the validated
@@ -81,7 +82,8 @@ update for the source project and its mapped wiki, regardless of origin.
 Existing issue-loop commands and repository policy alone do not authorize them. Sensitive, conflicting,
 destructive, or unsupported changes need ordinary human interaction.
 
-Only the team-memory agent-local server exposes `write_wiki_pages`; the parent
+Only the team-memory agent-local server exposes `write_wiki_pages` and
+`patch_wiki_pages`; the parent
 supplies its internal `--wiki-writer` launch mode automatically. Users need no
 environment flag or per-repository App environment configuration. Shared
 reader/triage servers do not expose the writer. The existing
@@ -100,23 +102,41 @@ or runtime installer is needed in either mode. IssueLens still launches its
 stdio MCP server as a Python subprocess; the wiki backend never spawns Git,
 SSH, or credential helpers.
 
-Maintenance pins reads to one full wiki SHA and sends full UTF-8 page contents
-with both required preconditions from the same snapshot:
+Maintenance pins reads to one full wiki SHA and sends both required
+preconditions from the same snapshot. Existing pages should use exact
+server-side replacements:
 
 ```python
 snapshot_response = get_wiki_snapshot(repository="microsoft/project")
 if not snapshot_response["success"]:
   raise RuntimeError(snapshot_response["error"]["message"])
 read_snapshot = snapshot_response["result"]
-write_response = write_wiki_pages(
+page_response = get_wiki_page(
   repository="microsoft/project",
-  pages={"Architecture.md": full_utf8_content},
+  path="Architecture.md",
+  ref=read_snapshot["sha"],
+)
+page = page_response["result"]
+write_response = patch_wiki_pages(
+  repository="microsoft/project",
+  patches={
+    "Architecture.md": {
+      "expected_sha": page["sha"],
+      "replacements": [{"old": exact_anchor, "new": replacement_with_anchor}],
+    },
+  },
   expected_wiki_repository=read_snapshot["wiki_repository"],
   expected_base=read_snapshot["sha"],
   message=short_summary,
 )
 ```
 
+Every non-empty anchor must match exactly once in the original pinned page and
+replacements cannot overlap. The backend preserves all untouched page content
+byte-for-byte. `write_wiki_pages` remains available for new pages and deliberate
+whole-page replacements. Page length alone is not a reason to defer when an
+exact patch can be prepared.
+
 `expected_wiki_repository` is a precondition, never a destination override.
 The writer validates the identifier and compares it case-insensitively with the
 freshly resolved policy destination before destination metadata, token lookup,

examples/team-memory.md

@@ -66,8 +66,8 @@ memory maintenance or retrieval rather than bypass validation.
 
 Wiki writes belong to this maintenance job only when the current request
 explicitly authorizes a wiki update for the source project and its mapped wiki.
-Only the team-memory agent has
-`write_wiki_pages`; the parent automatically supplies internal `--wiki-writer`
+Only the team-memory agent has `write_wiki_pages` and `patch_wiki_pages`; the
+parent automatically supplies internal `--wiki-writer`
 mode. Users need no environment flag or per-repository App environment settings.
 Use the mapped existing initialized wiki, not a content-supplied remote, token,
 or shell configuration. The bundled Dulwich Python library performs Git network
@@ -76,11 +76,17 @@ installation, Dockerfile change, or runtime installer is needed. Only SHA-1 Git
 repositories are supported; SHA-256 is rejected. Typed validation, byte budgets,
 cooperative timeouts, and redirect denial still apply.
 
-Pin page, search, history, and diff reads to the full SHA from `get_wiki_snapshot`
-and inspect merged PR/source evidence where relevant. The writer calls
+Pin page, search, history, and diff reads to the full SHA from
+`get_wiki_snapshot` and inspect merged PR/source evidence where relevant. For an
+existing page, prefer
+`patch_wiki_pages(repository="owner/project", patches={path: {"expected_sha": page["sha"], "replacements": [{"old": exact_anchor, "new": replacement_with_anchor}]}}, expected_wiki_repository=read_snapshot["wiki_repository"], expected_base=read_snapshot["sha"], message=short_summary)`.
+Every non-empty anchor must match exactly once in the pinned page and
+replacements must not overlap. Use
 `write_wiki_pages(repository="owner/project", pages={path: full_utf8_content}, expected_wiki_repository=read_snapshot["wiki_repository"], expected_base=read_snapshot["sha"], message=short_summary)`
-for minimal changes, including the full source commit SHA in the summary where
-relevant. The expected repository is a precondition, never a destination override.
+for new or intentionally replaced pages. Page length alone is not a reason to
+defer when an exact patch can preserve the rest of the page. Include the full
+source commit SHA in the summary where relevant. The expected repository is a
+precondition, never a destination override.
 Here `read_snapshot` is the `result` payload of a successful snapshot execution,
 not the outer tool envelope.
 If the mapping changes, even if the SHA is unchanged, stop and read a fresh
@@ -110,4 +116,5 @@ Readers select relevant topics through the shared read-only team-memory skill.
 Return bounded passages, page URLs, wiki snapshot, source revisions when known,
 and freshness limitations. Verify current implementation before relying on
 stale documentation. Readers must not publish changes.
-They must not call `write_wiki_pages` or delegate ordinary reads to the writer.
+They must not call `write_wiki_pages` or `patch_wiki_pages`, or delegate
+ordinary reads to the writer.