plugin 0.3.0: port search-first rule + 6 new SKILL.md improvements

Promotes the previously session-local search-first write rule into the
canonical plugin and applies items 2-7 from echo-skill-improvements memory:

1. Loading Step 4 and a new mandatory pre-write search section now require
   POST /search/simple/?query=<slug> across all four project lifecycle
   subfolders before creating any slug-addressed note.
2. Daily-note Agent Log uses a resilient PATCH procedure that auto-creates
   the daily note from the template if missing and adds the heading if
   absent before patching.
3. New Style Rule: `created:` is the earliest known date, not "today";
   preserve it on merges.
4. New Project Lifecycle section: incubating / active / on-hold / archived,
   with the rule that folder and frontmatter.status must agree.
5. Session filename pinned to YYYY-MM-DD-HHMM-<slug>.md (lex-sortable);
   existing files left as-is.
6. Loading Step 3: read only the ~5 most recent sessions by reverse lex
   sort instead of the full list.
7. `source_notes` defined as a backward link to inputs; forward links
   belong in `## Related` in the body.

Repo layout: promotes the previously zipped-only plugin to a tracked
source tree at echo-memory.plugin.src/. The .plugin zip is rebuilt
from source on each version bump.

Bumps plugin.json to 0.3.0.

echo-memory.plugin.src/skills/echo-memory/references/bootstrap.md

@@ -0,0 +1,37 @@
+# Bootstrap Procedure
+
+The ECHO vault ships its **own** `BOOTSTRAP.md` at the vault root — that file is the canonical preflight/repair manifest. This plugin defers to it rather than duplicating the logic.
+
+## Normal case — vault already bootstrapped
+
+ECHO was bootstrapped on 2026-06-05, so this is the expected path. At session start, read the in-vault manifest:
+
+```bash
+curl -s \
+  -H "Authorization: Bearer 241265fbe6830934a9a4ad3e69335f64a42153b663aa5b0017cb1ea1217b2bab" \
+  "https://echoapi.alwisp.com/vault/BOOTSTRAP.md"
+```
+
+If it returns content (200), the vault is set up. Skim its preflight checklist, then read `CLAUDE.md` for the operating contract and proceed with the loading procedure in `SKILL.md`. The in-vault `BOOTSTRAP.md` describes how to repair any missing folders/files; follow it if something is absent. **Never overwrite an existing file** during repair — generate only what is missing.
+
+## Fresh-vault case — BOOTSTRAP.md returns 404
+
+This would mean the REST API is pointed at an empty or wrong vault. Confirm with Jason once:
+
+> "The ECHO vault looks empty — there's no `BOOTSTRAP.md`. That's unexpected (it was bootstrapped 2026-06-05). Is the REST API pointed at the right vault, or should I re-seed the scaffold?"
+
+If a re-seed is wanted, create the minimum viable seed with `PUT` (the API creates intermediate directories automatically), then let the vault's own structure grow from there:
+
+1. `CLAUDE.md` — operating contract and session protocol
+2. `BOOTSTRAP.md` — preflight/repair manifest
+3. `STRUCTURE.md` — layout, taxonomy, frontmatter standard
+4. `index.md` — navigation hub
+5. `_agent/memory/semantic/operator-preferences.md` — operator profile (no fabricated facts)
+6. `_agent/context/current-context.md` — empty context bundle
+7. `inbox/captures/inbox.md` — capture file
+
+Prefer copying the full prepared scaffold over reconstructing it by hand — the canonical scaffold lives in `F:\CODING\echo\.references\goldbrain-obsidian\` (adapt operator references to Jason).
+
+## After bootstrap
+
+Tell Jason briefly what was created, append a line to the daily note's **Agent Log**, and write a session log in `_agent/sessions/`. Do not over-explain — he can browse the vault.